Thinking of putting my test pipe back in. I had my car tuned with the stock cat in and a Spugen dual oval exhaust and K&N FIPK only. If I throw my test pipe back in and do not get it re tuned will it be dangerous? Can the test pipe throw the AFR's off that much? Obviously it was leaned out when it was tuned, but to a safe level.

 

it will be safe! but if u retune u might pick up a few hp.

 

OK, yeah as long as it wont cause me to run to lean I am fine with not getting an extra 1-2 whp with the tune. Will wait for the tune when I get a header or something.

 

Yeah youll be fine. It might make it run a little leaner but nothing too serious.

 

It really depends on who tuned your car.

I doubt your tuner went agressive tune with VAFC.
And slightly leaner A/F won't make crazy detonation to blow up your engine.

But test pipe do make some changes on A/F, and you never know how lean it was before...ect


If I were you...
I would just re-check the A/F ratio just to make sure it is still on the safe side.