Quick history, 87 SE, V6, AT. Went down 13 yrs ago for coolant in oil. At the 10 yr point we (me and girlfriend) were moving and she asked "what are you doing with the Fiero? It doesn't run." So I said if it turns over it comes with us, if it doesn't you can call the scrapyard yourself. Hooked up the battery charger and turned the key, It STARTED!!!!!!!!! So in my excitement me and my buddy (Budweiser) decided we were gonna change the oil and top it off with some water and take it for a ride. Well my buddy was an idiot, spun main and rod bearings, trashed crank and cam. Here we are today rebuilt engine (my first). Started it the other day and timed it. Checked for leaks, while checking for leaks I noticed a 'snap crackle pop' noise from the catalytic converter, not very loud and only noticeable when I was very close to the cat. Had a minor coolant leak, hose clamp needed snugged. Shut the car off and while cleaning the garage I noticed very small goldish flakes behind each tailpipe. So my question is do I have a failed Cat and is something wrong with my rebuild that caused the failure? Only ran the engine long enough to get up to temperature, time, and find a leak (15mins maybe). Im no mechanic but IMO engine sounded and smelled normal. Thanks for looking and appreciate any answers.

Some simple possibilities....

-Since you only ran it for a short time, it is possible that you still had garbage in the exhaust system (I'm assuming you hadn't touched it during the rebuild).
-The ECM also needs to go through a cycle of idle, stop and go traffic and highway traffic to optimize itself. It could be running rich initially and needs time to stabilize.

You should also scan for codes and see if anything comes up.

Did you change your O2 sensor during the rebuild? Details of the rebuild would help.

If your oil pressure is good, no smoke blowing, engine sounds good, no change in oil level/colour, then you are probably good and just need to clean the exhaust out with a good drive.

The cat is scrambled, most of it will come out but some might stay behind and continue to make noise, it shouldn't hurt anything.

[This message has been edited by jmbishop (edited 08-20-2014).]

thanks for the quick responses gentlemen.

All original exhaust including O2 sensor, I know Im cheap. Being that this was my first rebuild I held back on buying anything new for the exhaust until I know its gonna run. Didn't check for codes, no SES light so I didn't see a reason to check, please correct me if Im wrong. Oil looked good to me, I even drained it and filtered it thru a coffee filter, nothing on filter. Coolant temp and oil pressure looked good. once up to temp engine idled about 1000 RPMs. Injectors were sent to Cruzenperformance for clean and rebuild, still have original cold start injector, and still using EGR. Built to OEM specs per service manual if that helps.

quote Originally posted by gtemplet: thanks for the quick responses gentlemen. All original exhaust including O2 sensor, I know Im cheap. Being that this was my first rebuild I held back on buying anything new for the exhaust until I know its gonna run. Didn't check for codes, no SES light so I didn't see a reason to check, please correct me if Im wrong. Oil looked good to me, I even drained it and filtered it thru a coffee filter, nothing on filter. Coolant temp and oil pressure looked good. once up to temp engine idled about 1000 RPMs. Injectors were sent to Cruzenperformance for clean and rebuild, still have original cold start injector, and still using EGR. Built to OEM specs per service manual if that helps.

It sounds like either old debris, moisture, or (as jmbishop says) failure of the Cat. I would run it a little longer. Take it for a gentle drive and see if it starts to clear up. If your cat is plugged or failing, performance will quickly start to degrade.

..,

[This message has been edited by tshark (edited 09-08-2018).]

Magnaflow makes an aftermarket cat for the Fiero. I had mine replaced in 2012. It was $160, plus labor to weld in place.

A replacement cat is only necessary if your car has to pass emissions and won't throw a code on the fiero so the only reason to replace it instead of knocking it out or deleting it is for emissions or preference.

quote Originally posted by tshark: Hmmm. If the cat is blocked, this could cause more issues, I believe. Just pull it and check.

From his description, it doesn't sound like it is blocked.

Thanks guys for the answers, girlfriend had been gone for a week and got back yesterday so I was banned from all things Fiero yesterday. Haven't taken it for a drive yet been waiting for front brake pads to come in (thermo quiets MX261) they were on back order. From everybody responses it seems as tho it's safe to drive. So once I get the brakes on and call the insurance company (huge fine in IL) I'll take her for a ride. I'll put a new cat on, it's not needed I don't have an emissions inspection, but I try to do my part for the environment. I like magnaflow but $160 seems pretty steep. I see Rodney has one for $110, any opinions on Rodney's? I'd prefer the clamp in Cats cause I don't have the means to weld one in. Thanks

Congratulations on the girlfriend. Too bad about the Fiero.

quote Originally posted by 85 SE VIN 9: Congratulations on the girlfriend. Too bad about the Fiero.

What ?

Always thought it was the other way around... ?

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Ben
87 GT / 88 GT
84 Indy #1863