P0430 Cat Efficiency Diagnostics

An illuminated check engine light has brought a 2012 Chevrolet Traverse into the shop. In this video, Master Trainer Drew Jablonowski of Garage Gurus shows the steps to diagnosing and resolving the problem. Drew starts by scanning the vehicle and it returned a code of P0430, which is catalyst system efficiency below threshold (bank 2). Follow Drew as he runs through the Walker five checks to ensure the catalytic converter is functioning correctly, including: scanning for PCM codes, making sure the vehicle is in proper fuel control by looking at fuel trims and checking for misfires; performing pressure test on cooling system to check for contamination; visually inspect the catalytic converter and look for exhaust leaks before or after the catalytic converter; and ensuring that the correct catalytic converter is on the vehicle.
Through this process, Drew discovers a pinhole leak in the exhaust system and replaces the Y pipe with a Walker Direct Fit Y Pipe. Retesting confirms that the issue was resolved and that there are no converter efficiency issues. Count on Garage Gurus to help you get your vehicle repair done right.
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For informational purposes only. We are not liable for any damages resulting from your reliance on this content.

[@ronaldmahoney1283]

Everything I"ve been told about exhaust leaks after the convertor didn't"t matter was a lie! This is the only video that explained it thoroughly. I"ve been fighting this po420 code for a very long time! It proves you can"t believe everything you hear! Thank You!

[@vegasboyorellana8205]

I honestly never seen a tech so good about specially po430 and the way you explain it you are a genius man I just subscribed even know I’m not a mechanic I just love to know anything about car fixing truly tank you for your free lessons

[@highquality85]

I have seen so many videos on cats/ codes of cat failure, etc, and read a LOT!! but none of them have been so clear, comprehensive and useful as this one. Great video! Thank you bro

[@TheWilferch]

Hint: for us DIY'ers...if you don't have a smoke machine to chase down leaks...you can do this--> on a cold engine, insert a shop vac hose ( exhaust side of vac)..... into the exhaust pipe, and spray the exhaust system on its outside surface and on all the flanges with a spray bottle of a mix of water and dish soap.....the "leak" will bubble-up clearly to see. Cheers.

[@valeriygorbunov9789]

It was very good, well structured presentation, one of the best I've seen on the subject. Kudos to Drew! Personally, I am not sure that exhaust depressurization after catalytic converter will cause such a symptoms with Sensor 2 low voltage reading. There's no much pressure drop along the exhaust, theoretically, you can remove remaining part after the downstream Sensor 2 and everything will be working the same (noisy though). Author's conclusion about no problem Cat looks correct, because Sensor 2 was low on voltage but steady. What I see, the new oxygen Sensor 2 installed with the pipe replacement, absolutely reasonable was not saving pennies on such a big job. Final verdict: Sensor 2 was aged and not performed correctly, burned pipe replacement was imminent. p.s. science and education wise, I would take a metal duct tape and wrap the leaking spot, my guts tell me the smocking would stop, but Sensor 2 low readings will be still there, so the "check the engine" warning, giving a precise diagnostic of the sensor malfunctioning.

[@michaelforeman6386]

Just subscribed. Wish I looked at this video before I bought/replaced my oxygen sensors! Turns out there were two pinholes on my flex pipe!! Thank you!

[@MarcusDurbin-caten8]

Best explanation of the 0420/0430 problem I’ve come across so far. Thank you! Excellent video.

[@michaelwaller5273]

Excellent explanation of the P0430 causes and diagnosis. Easy to understand. Thanks!

[@rafaelolanda9395]

This video is FANTASTIC! It's actually a Mechanic training video. Thank you!

[@alhuegayle7550]

This video was so detailed and informative in so many ways. Thank you very much for this. Keep up the awesome work.

[@ecclissiass]

This is by far the best, most detailed explanation of this code. Great attention to detail!!!

[@kentdavies1988]

This is by far the best video on this code I have found. You go through each step on what to check as root causes for this code BEFORE checking the cat. This helped me find an exhaust leak and I can't wait to fix it and check the live data. I am 99% sure this is causing my PO420. Thanks so much I will be subscribing.

[@emmanuelnsemoh9438]

Am so blessed with this video... What a true definition of tech.God bless you sir

[@billyyoder8171]

Thank you Garage Gurus. Good job. Have a blessed and safe week.

[@carlos-kx4sn]

Thanks for the time you took on making this helpful video. So well explained and so clear spoken. Thumbs up sir

[@mohamedosman8813]

Awesome video. I love the details you provided. Great job!

[@hmpllcorp-williams5131]

Awesome video and very detailed and packed with information.👏👏👏

[@chenus6544]

This is best car diagnostic education channel on KZbin. I watched you from Russia and recommend your channel to every car mechanic. Thank you so much for your help!

[@puffyelvis5895]

So often this is misdiagnosed as a bad cat - glad you explained (with O2 sensor graphs) how the p0430/p0420 can be set by the introduction of O2 after the cat

[@zuluboymechanic2481]

Well done. I have worked on these jobs but you have enhanced my experience

[@andrewmajors2552]

Drew this by for was one of the best video's I've seen and it was so professional had to subscribe to your channel.. awesome

[@KRColson]

Excellent diagnosis! Thank you.

[@lifeonthemark]

Great video! Very informative. Excellent content.

[@gailjohnson6670]

Excellent informative detailed video. Thank you so much for this. Blessings to you.

[@spelunkerd]

Brilliant work up! Always nice to make a less expensive diagnosis, ha ha.

[@PRGuanica]

Great video dude. Thank you for putting this video together.

[@DK-vx1zc]

excellent!

[@Jakburton44]

awesome job, great informative video.

[@atomwolf1]

Well done, thank you for the information!

[@blade_monstababy9945]

Best video I’ve seen. Great summary.

[@tombrownca]

Very Educational. Now to figure it (p0430) out on MY vehicle. Thanks!

[@dp6729]

Thank you very much for this, this will help me diagnose mine P0430

[@explorer97ish]

Excellent video!!!..Thank you so much!!

[@syedpervez7009]

Very helpful video. Thank you Sir. God bless.🙏🏼

[@CTSCAPER]

Great video Gurus!

[@vladislavpishiev3065]

Thank you so so so much for that video!!!

[@darrylgatewood9914]

Wow I learned a lot thank you very much!!

[@RMMR-po5xb]

EXCELLENT VIDEO!!

[@flacoface]

Great lesson!

[@michaelszabo6410]

Great video! Thanks!

[@cliffordgallagher4531]

I Have this code on a 2016 Honda Pilot, I Had to subscribe! Your Very Professional and Knowledgeable! Appreciate ya!

[@joshc710]

Did you get it fixed ?. I have the same vehicle and same issue.

[@cliffordgallagher4531]

@@joshc710 yes I did, they replaced All the injectors. And about 20,000 miles later the check engine light came on Again for the Same thing. So 2 weeks ago they all got replaced a second time. But dealer would only split the cost, not cover entirely.

[@cbarkwell1000]

Regret hearing about that Gallagher. As one of my Grandfathers use to say from East Texas , " Now that's a Scandal and a Shame". P0420/P0430 Checks : Catalytic Converters Below Threshold 1. Intake Manifold Leaks 2. Leaking Fuel Injectors 3. Incorrect Spark Plugs 4. Faulty Catalytic Converters 5. Ignition Timing Error 6. Coolant Leakage Fault 7. Technical Service Bulletin Fix 8. EGR problem 9. Oxygen Sensors Faulty 10. Oil or Anti-Freeze entering Exhaust 11. Hole in Exhaust before Front Oxygen Sensors 12. Silicone contamination 13. Road damage to CATS 14. Front/Rear O2 Sensors switched mistake

[@cbarkwell1000]

@@cliffordgallagher4531 2,000 Miles or 200 Miles Later, right. Surely not 20,000 miles , right.

[@cliffordgallagher4531]

@@cbarkwell1000 it was just under 20,000 later. Was about 10 months after the first set of injectors. Which should last longer

[@Takeover738]

So that exhaust leak was after the cat and downstream sensor and you say it still has an effect on that longterm reading?

[@Crystal-ge9gh]

Thanks Drew. How come no one mentioned this to me when I was told I needed a new cat converter?? I get it that it may have been damaged, but what about HOW it got damaged....I don't need a bandaid and continue to have a problem somewhere. That really fires me up. Thanks again, Drew, thank God for KZbin vids like this to reduce getting screwed.

[@danyeldan2139]

Damaging CAT from many thinks putting cheap gas , leaking coolant in to Exhaust system or engine burning oil or Fuel injectors worn this are main problem will damage CAT so quick if your car mileage is lower than 150K

[@Crystal-ge9gh]

@@danyeldan2139 Thanks!

[@damienbell3155]

Spot on great video

[@luisruiz7205]

Great video

[@admin7721]

Excellent diagnosis, thanks!

[@chrisjackson3391]

Thank u that helped me out a lot

[@bertjansen6689]

Very good info!

[@MsTiff-zh3ov]

Same vehicle same year. I hve replaced both flex pipes and the catalytic converter up front. Now I will hve o2 sensors and cooling system chkd because engine light still on SMDH. But very informational video!

[@andrewmvenegas]

Well done video.

[@bascondavid]

Very detailed and educative video.Thanks. Pls I got a misfire at idle.. what checks can I take to diagnose, car is carmy V6 2004 model.

[@khoirani507]

This is a fantastic video. Best one on the topic I’ve seen. Thank you! Is there another video on what you would do if the fuel trim was off?

[@cbarkwell1000]

Are you sure you wonna know ? I'll give you 90 % of the Ănswers. The Long Term Fuel Trim ( Air/Fuel Ratio ) Specs. are - 10 % to + 10 % @ Idle Speed & @ 2,500 RPM...If not, it's time to call Hôuston....The Smart Tech. Test all of thêse components & give thêse Pass ỏr Fail Results to the Customer : Positive out of range LTFT, say +25 means the Computer had to add 25 % to try & bring vehicle back to proper Air/Fuel Ratio ( 14.7/1 ) because òf this serióus Lean Condition -25 % LTFT means the Computẻr had to Subtract 25 % of Fuel to bring car back to propẻr Ảir/Fuel Ratio bêcause the cảr/truck ís Running Too Rich ( Fuel Ecônomy will Suffer ) + Fuel Trims > than 10 : 1. Ignition Systém Pass or Fail Results 2. Exhaust System Pass or Fail Results 3. Low Fuel Pressure results 4. Clogged Fuel Injectors Pass or Fail 5. Mass Ảir Flơw Sensor Fault 6. Oxygen Sensors Results 7. Vane Ảỉr Flơw Sensỏr dêfect 8. Manifold Absolute Pressure Sensỏ Fault 9. Throttle Position Sensor fault 10. Vacuum Leaks from Intake Manifold , hosés ỏr unmetered ảir from intake snorkel 11. PowerTrảin Côntrol Module malfunction ( The cars Main Computer ) Fuel Trim reading > than - 10 % but especially greatẻr than - 20 % & this Number ís fỏr Both ( - Fuel Trim ỏr + Fuel Trim ) : Test Results for : 1. Dirty or the Wrong Grade of Oil Example : Car calls for 5W-20 Motor Oil but Saw Mill Mechanics or DIYer sáy "Oil ís Oil", so 10W-30 Oil is ínstalled. I once worked for a real nice fella in Downey, CA. He put the WRONG GRADE òf Mổtor Oil in a Womans car. When she drove to thê Los Angeles Forest , her Engine SEIZED up on "er - going up those Steep A_ _ Hills....... ......I wunda how much that cost 'em... 2. Dirty Air Filter !! 3. Engine staying in OPEN LOOP Status Too Long 4. Clogged PCV Valve 5. Idle Speeed Too Low 6. Advanced Ignition Timing 7. Mass Air Flow Sensor Faulty 8. O2 Sensors Faulty 9. Engine Coolant Temperature Sensor Fault 10. Intake Air Temperature Sensor Fault 11. Manifold Absolute Pressure Sensor Fault 12. Throttle Position Sensor Fault 13. High Fuel Pressure 14. Leaking Fuel Injector 15. A Grounded Fuel Injector 16. Leaking Fuel Pressure Regulator 17. Low Compression from 1 or more Engine Cylinders 18. Incorrect Camshaft Timing 19. Faulty Evaporative components Is your Head Hurting yet ? Ex - Smog Repair Tech. Southern California

[@khoirani507]

Charles E. Barkwell wow amazing! Thanks! I won’t lie, makes me want to trade in my car 😂

[@khoirani507]

In my case, my long-term fuel trim on Bank to is 13% but that’s only while idling. When I’m driving it actually looks fine, so I thought it was a vacuum leak but I wasn’t able to find one

[@AUTOTUB3]

Wow that is awsome! 👍👍👍👍👍

[@alanchanthavisouk8557]

Can u tell me where u put the smoke test to test for exhaust leaks?

[@antuanmorales8465]

hi thanks for all the info

[@scottgshomewrenching1352]

You used Walkers test to check the Cat and they have some good info for testing, but I have had 2 GM's that I put Walker replacements on and came back with the same code. Install OEM cat's and light is gone and happy customers. In my opinion they need to do some more research on their GM cat replacements.

[@Itsleethe1]

This video was very informative, thank you. I’m looking at purchasing a 2013 lexus gs350 w this code and seller says it’s an 02 sensor and the code comes and goes. I paid a Toyota dealership for a pre purchase inspection and they said the code was not there so they couldn’t test for the things that you tested for. Could they have still tested for this even though I told them what the code was? I wanted them to test the sensors like you did but they said because there was no code they couldn’t do that. Seller has aftermarket exhaust and he says he feels it’s an 02 sensor but all the sensors are after the catalytic converter. Thanks for your help and opinion

[@josemarquez86]

Drew thank you👍🇺🇸🇺🇸🇺🇸

[@richardurteaga]

My question is if you got that error code do you have to change just the converter only or the converter and the pipe too

[@hugocortez340]

Wow I have replaced 2 catalytic converters on my 2009 chevy traverse and I still have that p0430 code and I chevy the flex pipe my car has a leak right the the downstream sensor I spent time and money and I only have to replace the flex pipe why didn't I see this video before

[@joestroner1639]

Thank you!

[@froylanmiranda7362]

Ever since I replaced my own spark plugs and ignition coils never had a miss fire come back. Wondering what can I use to do a smoke test at home

[@trublue2319]

Where do you connect smoke machine for exhaust leaks

[@aymaneng6763]

Good job

[@teju1908]

Wonderful thank you

[@jrbkay9008]

Thank you

[@bartleymcleod3544]

As of 06/25/2020 Ford and Lincoln has issued a recall for computer update for this code, they are also replacing the cats if needed

[@dreamkiss4u]

Hi I really would like to know what part and where did you hookup the smoke machine or smoke device to get it to do threw the catalytic converter to see if it had a pin hole leak? I would love to know so I can test my car as well because I have a bank 2 P0430 code as well please let me know or anyone who knows let me know asap thanks.....great video.

[@antuanmorales8465]

do you have a video of how did you use you smoke machine?

[@gameoversv5776]

Exelent explained and u checked all ways before say is the catalyst converter and we need to replace

[@CHIBA280CRV]

Fantastic thanks

[@jblack8149]

Where you located and how much you charge for all these tests?

[@leobardoperez9317]

I have a 2008 mustang gt with high flow cats can that be one reason why the code is up ?

[@pillarmechanix3178]

What would it mean if you had a long term and short term fuel trim spike to %110? Vehicle is 2012 Infiniti q56 with 5.6 p0430

[@BaysideSoundz]

Wow, I need to find a garage who can do that smoke test or if its possible to do it myself before deeming the sensors or catalyst bad.

[@hugoramos731]

Where did you connect the smoke machine into?

[@Chitown388]

wondering what kind of damages a prolonged exhaust leak (right before or right after the catalytic converter) would cause

[@cbarkwell1000]

If there í a small hole in the Exhaust before the 1st Oxygen Sensor, that's too much wind/Oxygẻn touching the Tip òf the Oxygen Sensor. The Oxygen Sensor will read this as a Lean Condition ( Lơw Voltage Constantly ). The Computer will try to correct thís Fault and will make the car Ảir/Fuel Ratio run Too Rich , thus making the vehicle fail fỏ High CO ( Carbon Monoxide ) on vehiclés in California up to Model Years 1999 ______ and some Smog Techs or DIYers will have Customers paying fỏ components that make cars Run Rich......In Reality, it was a Hole in the Exhaust System , that wás the problem ( which he showed ). Never woulda known the real fault if Smoke Machine never was used. The Front Oxygen Sensors Voltages should be switching faster than women blinking thẻi eyes at a man.....Rich Voltage to Lean Voltages quick & constantly. Smog Repair background Southern California

[@yz250a]

Make sure to wet pressure tester adapter seals with coolant, or you may get false leak result.

[@stephenaddair]

Im getting a p0430 code and every once in a while ill get a check coolant level pop up on my dash but it goes away and my coolant over flow is full my car is a 2005 corvette ls2 with 120000 miles so i should have a pressure test on my coolant first? Im not using any oil or any smoke from exhaust but when I bought the car a couple months ago it did have the mufflers off and it came with a bolts s type exhaust that I had installed and after that is when my engine light came on the first time the next day after I had the borla exhaust put on

[@isrealperez9069]

I'm curious to know when the light comes on for 4:30 you know the vehicles to run very well and your upstreams and downstreams work very well now but the field trim is a little bit different explain

[@TheWilferch]

If the car suffered a slight oil overfill condition to cause the 420/430 code to trip.....will getting the oil level down later help..or is the "damage" done and can't be recovered ?

[@mohamedbenameur76]

I have chevrolet trailblazer 2017 before 2 days the P0430 code appear . Please i need help.

[@harpazo1514]

seafoam in my gas tank turned my lights off for bank 2 does that mean problem no longer an issue?

[@imontopx1261]

can an exhaust leak in the tail pipe cause the code to turn on?

[@albertmashburn6030]

great video , you are good at this , you make me want to buy me a scanner

[@themeparkdad]

Nice video but a little hard to do at home without all of that equipment. You didn't show the smoke machine so I don't know if that is expensive to get but in this case it was necessary. I have see conflicting information on how long a catalytic converter will last. I have seen it posted it will last 'the lifetime of the vehicle' and also posted as needing replacement at 100,000 miles. Since my 2006 Toyota Sienna has 170,000 miles should I normally expect to replace it at this mileage? I pulled a code on the downstream O2 sensor (bad heater) and replaced. P0430 code showed up next so I replaced the upstream O2 as well. Waiting to see if that fixed it...

[@michaelforeman6386]

I put my leaf blower in my tail pipe on lowest throttle and sprayed soapy water all around my exhaust and found my pinhole leaks.

[@originalorange1503]

Can a bad oxygen sensor cause a p0430 code ?

[@JustinMentionedIt]

I’m getting this same code but my Acadia won’t start , I got it to start and run for maybe 2 seconds with a really bad rough idle I guess you would say, I’m guessing this isn’t my problem then?

[@stevencohn39]

I JUST BOUGHT A 08 KIA SEDONA WITH A P0430 CODE. AND I AM TRYING TO USE ADDITIVES TO CLEAN OUT THE SENSOR/CONVERTER, IF IT DOESNT MAKE THE LIGHT GO OUT I WILL THEN TAKE THE CAR IN TO CHCK FOR EXHAUST Y PIPE LEAK AS IN THIS VIDEO.

[@elmermelara6462]

Can the same rule be used to diagnose po420

[@mohamedjamal8344]

Best of the best

[@Fred-gt4zu]

Great job very informative. Any advice on how a DIYer may be able to do such a job but does not have and/or able to obtain those nice toys ( smoker, coolant pressure tool etc. ) and keep from visiting a technician shop?

[@Wildwwill]

I'd like a smoker for a number of reasons, like checking turbo intake piping. The coolant pressure tester I have rented from autozone. It worked well to find a stubborn hard to find coolant leak on my sons vehicle.

[@MindsEyeVisualGuitarMethods]

I have one of those apps for OBD2 diagnostics. I couldn't figure out which gauges are for fuel trim but the bottom O2 sensors sweep pretty wildly from low voltage to high voltage. So I suppose that means bad cats. And I think on this 3.5 EcoBoost you can only fit an a spark plug oil Fowler on one side. But both my cats fire off a code. One thing I noticed since I bought the van is it's been overfilled with oil by a little bit even when I change the oil recently getting used to how much it actually takes versus how much the manual says it takes. If it's been suffering for many miles of extra oil blow by, should I just consider the cat's hosed? I've tried lacquer thinner, cataclean and a product from rislone and they all kept the codes off for a couple miles but that was it

[@Wildwwill]

Odd that both cats would be bad. Sometimes these engines build gas in the oil due to running too rich. That could be caused by a number of reasons. Bad or weak sparkplugs or ignition coils etc. Oil in the exhaust may be a build-up in your intercooler. That comes from the pcv valve. Also, those PCV valves are known to go bad allowing turbo pressure into your engine which could intoduce oil into your exhaust.bad turbo bearings or seals could do the same but its unlikey both sides go at the same time , which leads me to believe you have one of the aforementioned issues.

[@sertimins]

I don't understand why you couldn't catch the leak from your o2 reading and had to do a smoke test. Why did you change both y pipes if code was only for bank 2.

[@abdainawi]

Hi bro.. I recently bought ls430 2003 with 200k miles on it & it makes match stick burning smell every time I sprint hard.. Which goes away after few runs. But repeats every time I drive car.. All say it's catalytic converter.. Any clue

[@carolr.556]

Excellent video..I need to do all of these checks to see why there is a P0420 code..

[@cbarkwell1000]

See Gallaghers Comment Section.

[@henryg2350]

What’s the scanner and software used in the video ????

[@leo4870]

What happened if I feel a small misfire and have a p0430

[@typisoha]

What if I delete it and install a piece of pipe??

[@fel1xxpubg972]

See kids, this is why you take your car to you local shop were they try and save you money and not these big shops where all they do is swap parts instead of actually fixing it.