IwannaFC

hey guys, i had to drive to the muffler shop the other day by just runing it off of my Downpipe (RB 3") becuase the rubber hangers on snapped. I wanted to get a new exhaust anyways so i decided to go to the muffle shop. (the old exhaust was not fixable or reboltable) i drove my baby to the muffler shop where they installed a full 3 inch stainless exhaust. Now b4 when my exhaust was still on, my A/F guage was reading about a little over half way (if my memory serves me correctly, it was an autometer guage) after i got my new exhaust put on, the guage reads ALL the way RICH. What could the problem be? i did have a ear deafening backfire on the way to the muffler shop. Could that of damaged my O2 sensor? did my MAS decide to coincidently go bad? im also having a hesitation now. You guys know how on the pedals on our cars have a soft spot b4 it hits the hard spot to push in? it does it right at the borderline and my A/F guage starts reading lean. It misses pretty bad and hesitates but as soon as i left off a little bit or start boosting a tiny bit, it goes away and my A/F reads full rich. does anyone know whats going on????? id appreciate any help -alex

Aaron Cake

iTrader: (1)

Sounds like they disconnected the ACV valve or removed the belt from the airpump.

Have you done full tuneup lately?

IwannaFC

i removed my airpump. I had an RB TB exhaust b4 when it was fine, after the mounts broke i decided to get more of a "japanese" look to it or more Ricey as some people may call it. It was only until after they put the new exhaust on it started doing it.

Digi7ech

iTrader: (1)

Well maybe since the exhaust is now restrictive it is causing a richer condition.

Just a guess.

Aaron Cake

iTrader: (1)

Then the reason it backfires is because you have installed a new, free flowing exhaust and removed the anti-afterburn controls. The hesitation is probably due to an unrelated problem (typically TPS).

The A/F gauge behaviour sounds completely normal in this case.

IwannaFC

well the major backfire that i had was when the car was being driven off the DP and the DP only while i was driving to the muffler shop.

IwannaFC

bump

HAILERS

You know how in the fsm they have you hold the engine speed to approx 2000 rpm, and then with your finger move the tps inward momentarily????? And how the when you do that the engine speed will fall? Yeah. Of course you do. That is the result of the fuel being cut to the injectors. That happens each and every time you are driving and let off the throttle. So with that in mind....go out there and hit a home run by setting your tps and while your at it ohm it out for dead spots. It sounds like you have one in the tps...maybe/maybe not.

Oh. And the 02 should read low when the injectors are cut off.

IwannaFC

when warm my A/F reads full rich at idle as well.