mustangcruzin

So I had an off road pipe on my car guys and as much as i love the smell of no cats.. my car smelled bad.. really rich and it worried me when i passed cops. If i do a SCT tuner will that adjust my A/F so the car doesnt smell as bad. Im going to do the tuner anyways to turn off the rear 02 sensors...

if it helps any i ran the off road pipe with no mil's or no tuner... and LMI mufflers.. which im also changing.

Thanks Guys

SilvrStang

It will run a little rich when you run an O/R H pipe. Even when I turned my rear o2s off it still smelled a tiny bit.

cliffyk

An o/r pipe will not affect AFR, it can't as there is nothing about the injector pulse width calculations performed by the PCM that has anything to do with the catalytic converters. The rear sensors are ONLY used to monitor the efficiency of the converters and have nothing to do with engine control.

A wideband O2 sensor will easily confirm this, it will smell rich without cats.

One thing that would make it run rich would be an exhaust leak before or near the front O2 sensor(s).

mustangman281

+1 to what cliffyk just said. He is exactly correct.

MJH78

After I put on my OR midpipe it didn't smell all that rich to me. It seems to smell more rich now than it used to. thought it might have a leak because if the leak is before the front O2's it will fool the O2's into thinking the motor is getting too much air and it will correct by sending more fuel. TOok it to the exhaust shop and they said it's not leaking.

mustangcruzin

hmm... mine was just rediculously rich.. like i have buddies with stangs that smelled no where near mine.. and i no there was no exhaust leak.

defconfire

take it to a dyno or find someone with a wide band O2,