Im about 90% sure my front O2 sensor is going bad but Id like to hear from you guys.
What are some signs that the front O2 sensor is going bad?

I threw code PO134 once but I cleared it and it hasnt come back in over a month

Also, the car will sort of "blip" once when I let off the throttle in any gear (weird) and if Im at low rpm (giving it throttle) in 1st or 2nd the car stutters and bucks until I give it more throttle or push in the clutch. The cars idle and fuel mileage seem to also be getting worse but Im not sure if there are outside circumstances contributing to that.

My mods = 280 i/e comp cams set at -2/0, 3" tbe, mbc, fuel pump, BR intake, JDM DV, custom road tune by AL

any USEFUL comments would be appreciated and yes Ive searched so dont be a smart a$$

Chris

 

+1

 

Best way to tell is to watch it on a logger. The sensor gets pretty lazy when it starts to fail (cycles slowly). Bad mileage and black smoke out the exhaust are other symptoms I've had, but I couldn't see the black smoke, friends that knew my car well enough pointed that one out to me

 

Mine has black smoke and it throws codes 1 to 2 times a week but they go off.

 

when mine went on my 03 8 the first sign was bad gas mileage.

 

+1 on the bad, bad gas mileage. The worst I've done so far was 15avg with heavy driving. If youre getting alot less than that I would worry. I hear the K&N filter can ruin the maf with too much oil. Maybe it would be possible to screw up the o2 sensor as well...