I have an 03 350Z (build date 8/2002). I installed test pipes and an aftermarket exhaust system. I NEVER had the SES light come on with this setup. Well I recently swapped out the test pipes and put the cats back on an now the SES light is on??? I tried the ECU reset procedure, but the light comes back on after 10 minutes. Any reason why this would happen now? I find it irionic that the light did not trip when I put the test pipes on initially, yet now that I put the cats back on the car, the SES light is on. Any help is appreciated.

 

Very strange.
The oxygen sensor is damaged?
Can you go to AutoZone and get the error code read?

 

damaged sensor

 

Engine code reads P0037. I checked the O2 sensor. No damage to it.???

 

check for leaks?

 

My system is TIGHT!

Thanks tho...

 

From what I've read, if the light comes on quickly after it has been reset then the sensor is bad.

I would have to assume you damaged the sensor when you swapped in the cats. The element inside the o2 sensor is very sensitive and easily damaged.

If you pull the code it will tell you what sensor is bad.