That works

 

My Evo is an 04. My friend told me it might bcause all my stuff is brand new and hasnt been filtered through enough so the 02's arnt reading right but when it gets used a little more they should react better.

 

Will an Service Engine light ever just turn off by itself or do you have to reset the ECU?

 

Only if you unplug the battery but it all depends on which year Evo you have and if you still have the problem it will keep coming on.

 

Yes Sir

 

Go to your local parts store (Checker, Napa, etc.) and borrow their OBDII reader. Connect it and pull the code. It is most likely a P0420 -- CAT inefficiency. It is always nice to know what code you are getting. It will also have an option to reset the code – easier than unplugging the battery for 20 secs and having to reprogram the radio.

If it is a P0420 then do what MYEVOVII suggest and do the O2 extension. It is a cheap and effective solution.

 

Why would my engine not come on right after the whole turbo back was put on? I drove it for awhile with no engine light.

 

You have an O2 sensor in the O2 housing before the down pipe and then another after the CAT. You will get a P0420 code when the ECU compares both and finds little difference. I have read that it only does this check after everything is up to temperature and you are cruising -- I have no way of confirming this. However, it is consistent with my experiences as I only ever got this light in this situation -- specifically I found I would get it consistently on cold mornings, cruising along the highway. I never got it during aggressive driving or when the car was warming up. It could also be that it takes an average of the reading over time.

Do the O2 extension. It is cheap and really easy!

 

Where Can I get the 02 extension and ow do you install it?

 

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