help needed with a 2002 STS

[JayBay]

I'm trying to help out a buddy with a 2002 STS and a limited budget. He recently had a tune-up done by a non-Cadillac mechanic. Just to clarify, this is a certified mechanic, just not a Cadillac mechanic. He did plugs, fuel filter, and tranny service. The hope was that all this would clear up a rough idle and cause an increase in fuel economy on a 100k caddy. After tracking down a vacuum leak in addition to all the work, the rough idle went away and the fuel economy went up. However, the check engine light has reared it's head again, and the mechanic said the code indicates catalytic converter failure. The car seems to run great - but it won't pass emissions inspection with the check engine light on.

So - assuming this code is correct and the car does need a catalytic converter, we began research on replacing it--only to find out Cadillac sells it as a unit with much exhaust pipe on either side to the tune of $1000 for the part alone. Finding this unacceptable, we checked some other resources. When entering year, make and model, most online parts stores kick back a "universal" catalytic converter. This brings me to three questions;

1. Will the universal catalytic converter work? (Understanding the old one would have to be cut out and the new one welded in).

2. Is it possible that the code is erroneous, and possibly caused by the lean conditions that existed prior to tune up?

3. I've read a few references on this board to on board diagnostics. Can somebody post a reference link where I can learn more about this?

Thanks!

 

[glanga]

Have you tried disconnecting the battery overnight to let the car's ecu reset itself? I know the northstar system and seville's electrical system alone is very finnicky and most non-cadillac mechanics ive gone to wont even touch the car. also, the cel could be being caused by a bad o2 sensor.

this is all just "advice." im not an expert on the car and have always taken it to a cadillac dealership to be serviced.

you can always google the dtc to see what it means and what it could be caused by

 

[Dadillac]

On the right side of the instrument panel, with the key in the on position, simultaneously hold the info ^ button and the on/off button. After about 4 or 5 seconds the dashboard will go black, and then light up again. It will say "codes", press the on/off button. Then it will sat "all codes", again press the on/off button. The codes will then scroll through automatically. Right down the codes, noting if they say current or history and then post them here. It will help out with helping your cause.

Don

 

[CadillacETC1997]

emissions warranty is 8k 80k
if your under that then i suggest you just have the dealer do it for free but im assuming since you say 100k Caddy its over that????
just making sure 1st