Another check engine light question

[Heavy D]

After installing a new exhaust on my '95 240sx, the check engine light came on. I'm assuming this is because the new high-flow cat is now behind the second O2 sensor. I can make the light go off temporarily leaving the battery disconnected overnight, but it always comes back on within a week or so. If I were to just leave the light on until I can get the O2 sensor moved behind the cat, would it present any performance or gas mileage problems?

I know this has been asked a thousand times, but no one has really covered what will happen if the light is just left on due to this issue.

Thanks for not hating/flaming

[hybrid_flyer]

nohing will happen, it just means your emissions are high

[Zydeco]

and if your in cali you wont pass smog with your check engine light on.

[Ligouri Rd]

http://o2simulator.com/-nuff said.

[ddgsxr504]

Pull the code off your ECU and make sure the CEL is on because of what you think it is. Then you can dump the code off teh ECU but unless you fix the o2 problem then it will come back on. I just pulled the gauge cluster out of my car and removed the bulb from the "check engine light" because my CEL will never go off with all I have done to my car! I have removed my EGR, AIV, and have a Hot shot header, Apexi 3" N1 exhaust, 2.5" test pipe (instead of CAT), JWT Cams and Tuned ECU.