Engine Light on 2000 GTS - HELP!

[VOI9 ASP]

I have a 2000 GTS. After my borla exhaust and edlebrock headers were installed and my car was returned to me the engine light was on. It is still on and no one has any idea what the problem is or how to repair it. I have been told it may have something to do with the mods that were added. Any ideas? Help!!!!!

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[Ulysses]

Hey Jerry,

Were the cats removed, or replaced? Might want to take a look underneath and see if the O2 sensors were reinstalled properly. If it was hooked up properly, it may take a few drive cycles to cure the light-on symptom. I guess, give some more time and re-access.

Ulysses

 

[Mike Brunton]

Jerry,

I vote for the O2 sensors as well. They are really the only thing I can think of that would trigger such a light from exhaust work.

The only other super-simple thing that can cause a light is an improperly tightened gas cap - might want to check that if you (or the shop) filled up the car and didn't cinch it down tight.

Let us know what it ends up being -I'm curious

 

[VOI9 ASP]

The work was done by a good Viper Mechanic in Northern California. I have put a few thousand miles on the car with numerous fillups. The mechanic doesn't seem to know what is causing the problem. I believe he already checked the O2 sensor. The light was not on until after the car had the exhaust and headers installed. Could a slight break or leak in the header gasket cause this problem?

Any other help would be greatly welcomed.

 

[HouseofSpeed]

Jerry...the MIL (malfunction indicator light) has stored a trouble code and should be accessible to your technician through a scan tool. That would tell him what the PCM thinks the problem might be...get that info for me and maybe I can help. Rear O2 issues are big on the list for 2K Vipers that have exhaust mods....let me know. Thanks.

 

[Jay Herbert]

It is caused by the O2 sensor. Sean Roe (of Roe Racing) and Hennessey both offer, or are planning on offering, an inline (connects between the O2 and harness) electrical doodad to address the problem. The HMS one is $175/pr and Sean was talking in the $75? range. Your car's timing is likely being affected negatively (from the perspective of performance) right now. The cause is a computer change that occurred.... starting in 2000(?)

 

[AviP]

There are two O2 sensors, one upstream and one downstream of the cat. Removal of the cat or installation of some aftermarket exhausts could confuse the downstream O2 sensor into thinking that the cat is not working right. I believe this has been documented frequently. In theory, you have to fool the downstream O2 sensor or chip. Vehicles after 96 (maybe 95) only have the downstream O2 sensor?

As a historical note, it was the EPA requirement of adding this downstream O2 sensor that resulted in the exhaust being routed via the back instead of the sides.

-Avi

 

[Nadine UK GTS]

A while ago I was trying to think of a way to 'fool' my PCM on removing the cats with the rear O2 sensors (maybe with an inline resistor or something) but then I discovered my 1997 does not have rear O2 's. Apparently the European Export Vipers don't! Don't know why? I know my PCM differs from US spec to account for a different fuel octane rating over here, and I guess it obviously knows it doesn't have rear O2's!