Pontiac Firebird Trans Am Ignition Diagnostics part 5: Catalytic Converter!?

[@Gutter_bird]

Glad you finally tracked it down, Biff. What a pain!

[@michaelm3381]

I'm impressed you are the original owner. I love these cars.

[@pdennis93]

Yup. Not a lot of original owners left. I'm the 2nd owner of mine, but I've owned it for 18 and a half years.

[@johnevans3892]

Best opening yet.

[@leoamaya1818]

🎉Congratulations!!! now it’s time to install headers & exhaust 👌🏼💯 🇺🇸

[@upssidep9283]

PRICELESS SMILE! Great job brother!

[@johnevans3892]

Had things I needed to get done today. Going down your KZbin hell, first with the stinger than two the trans am my soul is healed now seeing the solution. Great perseverance.

[@paulkukiel3725]

Great job, Biff! Loved seeing the beach opening and closing as well! 👏🏼🤓

[@ronchang9791]

It's always a good day when an lt1 issue is resolved! 👏 Maybe all those cat thefts in my apt were just people trying to resolve their car issues 😁. Jk, I shouldn't be joking as my LT1 f-body just got broken into 😮. Can't wait to see the next vid!

[@ScannerDanner]

11:52 I know that smile!! Nice. Thanks for the mention. For your viewers, you can pull the upstream O2 sensor and measure your backpressure at that location. Should be no more than 2 psi at 3000 RPM in park. Then you won't have to cut your exhaust to be sure. Another method is to simply remove the upstream O2 sensor or sensors and then drive it briefly to see if power is significantly better, if it is, this also confirms what you found. Thanks again! This is one of the first videos I ever did on KZbin so forgive the camera work but this is a good one for back pressure testing kzbin.info/www/bejne/b4XPqpqAgt2HptU

[@FearlessMods]

@ScannerDanner…thank you for the comment, the view, the suggestions and for being cool about it! I subscribed as I was working through my issues with this car and absolutely value and love your content…especially as a Picoscope owner (now!)

[@ScannerDanner]

@@FearlessMods can't go wrong with the Picoscope! I have a video or two showing how to use an in cylinder pressure transducer connected in place of a spark plug to measure for a plugged exhaust too! Nice to meet you btw

[@stanleysapyta8928]

I had the same issue with my formula... I couldnt go over 60 mph no power random misfire..and liter no codes... Took it to the exhaust shop and they said I had a clogged cat... Now it runs amazing...wish I would have seen this sooner since I literally went through the same thing you did!

[@03Lorac]

Hey B. I cannot believe it.... You've finally figured out the gremlin....bravo! What a pain that was! All that frustration and money. No regrets though because at long last, your bird is back to life. I'm gonna start using that cat cleaner product to prevent the clogging. My 95 has around 53k on the clock, so i can benefit from preventive maintenance. She's a beauty....keep enjoying it. I'll post a video of mine on my channel sometime soon. Fbodies 4 life.

[@genthba]

Heck yeah! Congrats!! I bought my 1995 in 2006 and had the Cat cut off within a week of owning it haha.

[@kevintapia7297]

The same thing is happening to me 😂 I bought a 94 formula 2 weeks ago and is missfiring like crazy, and I’m looking forward to replace the optispark, spark plugs and wires to see if that fixes the problem.

[@americanmotorsam-caz524]

Used the Gary 94/95 pc program and you could see map pressure was pushing almost 50 which was way high. I drilled a hole thru the front of cat pipe header put in scope from Harbor freight and saw the cat had collapsed

[@DanielChristiansen]

You had a misfire for a long time, and it killed your cat. :) When a misfire occurs, the unburned fuel and oxygen mixture enters the cat where it combusts and melts the honeycomb. I'm glad your beautiful car is back to running as good as it looks!

[@FearlessMods]

So you’re saying that somewhere along the way I was actually successful in fixing a misfire…we just don’t know when or what it was?!?! 🤣🤣🤣

[@DanielChristiansen]

@@FearlessMods Catalytic converters are not a wear item, they last the life of the car unless major engine issues kills them. Lets hope your efforts has cured the DTC41 error (ignition related) and it doesn't pop up again. 🤞

[@y.g.smokedog3233]

That might be my problem with my forth Gen . Thank you for the video!

[@anthonyraue4170]

I bought my 25th TA from my brother who bought it brand new . He had the engine rebuilt and tuned by Ron Zimmer. It was a CA car , I'm in MT. So I removed all the smog stuff and the cat. Since there is not an O2 sensor after the cat. It's dyno'ed 425 hp at the rear wheels. It is a beast.

[@FixItStupid]

Right My LT 4 Cam & Heads Set Up Makes That SO Fun 1994 TA GT From NEW

[@EHUE-kf4ey]

OVERTHINKING A PROBLEM, i'VE BEEN THER SEVERAL,SEVERAL TIMES . GREAT EPISODE

[@CashMullen-ng4sr]

Just pull off the cat, hollow it out with a hammer and crowbar and bolt it back on.

[@mprce52]

hahahaha great intro

[@just_2swift]

I wonder if this is whats wrong with my 96 Camaro RS? 🤔🤔🤔🤔🤔🤔

[@jaybrown679]

brother Biff I have a white 94 Trans Am having a issue ,,,, been following your progress. My issue is definitely not a clogged Empty cat . lol is there some way you could direct message me ?ill have you stumped on the pico scope. 🙃💯

[@FearlessMods]

Biff8892@. Let me know when you’ve got it and I’ll pull it back down.

[@WatchTowerJ]

So are there no O2 sensors sending an SES to your dash board? I have heard you need to spoof the o2 signal when you lose the cat.

[@FearlessMods]

Not happening. And I just drove it several days in a row for a couple hundred miles at Firebird Fest!

[@CashMullen-ng4sr]

This is 1994, prior to OBD II in 1996.

[@pdennis93]

I still have the factory cat on my 95 with 165k. I wonder how mine looks.

[@FearlessMods]

Well now you know not to waste 10 years replacing parts when it starts to go to shit! 🤣

[@teddybowman215]

My problem has never been in neutral. While revving in neutral always sounds good. my problem has always been once I put it under a load, i.e. in drive. It stumbles until I get past 2500rpm or if I smash the gas it slowly ramps up

[@teddybowman215]

But I'm learning from your videos and am excited to work on her again! I know my driver's side cat is bad!

[@collinsmus1]

Did you ever fix the abs light problem? I fixed mine.

[@FearlessMods]

It’s intermittent. Had it the other day and then didn’t… 🤷🏼‍♂️

[@collinsmus1]

@@FearlessMods what fixed mine was replacing a burned out brake light bulb in the rear hatch spoiler. On my 1995 z28 that burned out bulb shuts down the entire abs system. It breaks the circuit. I spent about 500 dollars replacing parts before I found out what it really was while reading on a forum. You could have a intermittent bulb losing connection.

[@FearlessMods]

WTH!?!? Damn engineers…and I AM one!!! 🤣🤣

[@genthba]

@@collinsmus1 thats great to know!

[@tristanlemoine-lv4rb]

Hey I have a 94 firebird having problems is there an email I could get to ask some questions about it

[@FearlessMods]

Better to ask them here Tristan, then the community can offer suggestions. Took me years to solve mine, but I was appreciative of all the tips and suggestions received here in comments even when they weren’t applicable or didn’t work.

[@Thirdgen83]

Can a clogged CAT cause a rich idle?

[@FearlessMods]

ABSOLUTELY! Mine would water my eyes!! Think about it...the exhaust is struggling to get out and the engine just keeps adding fuel on each 4-stroke intake cycle, so it can get pretty rich. At least that's how I visualize it. If you look at my previous videos on Ignition Diagnostics, that could explain some of what was going on with the crazy spark lines.

[@Thirdgen83]

@@FearlessMods Well now I'm wondering if mine is plugged up. It's the original 38 year-Old CAT. I'm not running a ECM. It has a non-computer carb and distributor. I've tried 3 different carbs (2 Quadrajets and one Edelbrock) and 2 different distributors. Spark plugs & wires are new. Exhaust at idle stinks and burns eyes. Timing is adjusted correctly. I'm at my wits end. Still need to verify fuel pressure (mechanical pump), but this video has me thinking about the CAT now. The exhaust even sounds weird at idle, but normal at higher RPMs.

[@FearlessMods]

It just seems odd that it’s OK at higher RPMs. You may not have this equipment (I don’t) but this is a good video to help isolate the problem. kzbin.info/www/bejne/oYCcYqZmeNSAlZY Worst case, you can pull out an O2 sensor upstream from the cat or drop the pipe all together and let her rip to see if it fixes the problem.

[@rebolhais]

Hi ,but without cat. The Toxic Gase came in cabin.

[@FearlessMods]

Nope. Right out the tailpipe like every other pre-catalytic car. But…that’s only with the empty cat reinstalled. Works for verifying the problem, but the right answer is to have it replaced after it’s verified.