mzeitlin

I recently replaced an O2 sensor (bank1 sensor 1) following a check engine trouble code for that sensor.
The code cleared, but I noticed the car now has poor acceleration. It is very 'jerky' when leaving a stop or at speed and accelerating to pass.
The engine idle is also not as steady as before, but it is not bad either. When I accelerate the engine by hand under the hood (in park), it revs perfectly (no load).

Any suggestions what to check when there are no trouble codes to follow? I already cleaned the MAF (which is one year old) with no change.
The car runs fine at steady speed - only when I accelerate as when entering a freeway or moving to pass.

List of possible issues I am thinking include:

1. VVT solenoids.
2. Throttle body
3. intake hoses (no signs of cracking, but they are original)
4. charcoal cannister.

Thanks ...

PFB

I would start with your No 3, but you'll have to remove those rubber snorkel hoses and carefully bend them slightly and look for cracks. Also see if it does it in reverse. If its a cracked hose it should not do it in reverse.

Phil

mzeitlin

I should try accelerating in reverse to check?

PFB

Yes. Accelerate in reverse. If symptoms are there, than it's not a hose. If no symptom than probably it is a cracked hose. But again, best to remove them and examine them very carefuuly

fortitude

Was it an A/F or O2 that you replaced? What was the brand name? And the symptoms you state occurred only after recent bank 1 sensor 1 replacement?

mzeitlin

Air flow and oxygen sensor are the same thing (trouble code 1130 & 1135). I replaced the existing Denso with the same one (same part number). Trouble code has not returned.