03maximaguy

My car has been bogging under acceleration. Its almost like its dumping too much fuel or something. Replaced afm with new one about a month ago. No codes are showing up. tonight i used the torque program and obd2 adapter to test sensors. to my understanding voltage on 02 sensors are supposed fluctuate up and down between 0.1 and 1.0 volts. sensor 2 on both banks did not fluctuate. they both just stayed at 0.25 and never moved up in voltage. would this indicate they are bad? sensor 1 on both banks fluctuated in voltage.

Chris Gregg

iTrader: (59)

Yes, they a supposed to fluctuate as well, however...the secondaries have absolutely nothing to do with fuel management if your primaries are working. Interesting you're not even getting a pending code on this, I think it would read "slow response" or something like that.

03maximaguy

These are the readings I've got.

03maximaguy

Just posting to update on how my car has been behaving. appreciate any input before i replace anything else.
Car has always had slight hesitation in acceleration for past year or so. Never thrown a code and has good gas mileage. runs great other than the hesitation/bog about 50% throttle. Always figured coil, maf, injector or 02 sensor.

when I made the original post was because the car was bogging badly when you stepped into throttle. very noticeable power drop. No codes but 02 sensor voltage for sensor 2 on both banks did not fluctuate in voltage.. just flat lined at one voltage and stayed. sensor 1 on both banks fluctuated up and down in voltage as they should. this has me thinking o2 sensor issue.

Day after original post, finally threw a code. P0302. misfire cylinder 2. scan tool also mentioned 02 sensor threshold voltage out of spec. I have been running cheap gas lately. 93 octane but cheap (quick trip).
Cleared the code and filled up with Bp 93 octane. The car has not thrown the code again and is back to only the ever so slight hesitation. 02 sensors are no longer flat lined on voltage and now fluctuate, if kind of slowly. when i scan sensors the 02 sensor threshold voltage is checked as good.

The car now has 180,000+ on her. does this sound like beginning of 02 sensor and coils failing?

02whitemaximase

iTrader: (38)

Cylinder 2 coil could be on its way out. When one of my coils was going bad the hesitation was pretty pronounced. I usually got a flashing cel too.

03maximaguy

Drove the car hard on the way home from the drag strip last night. Once I got off interstate I noticed that there was a slight stumble in the idle. Later the check engine light came on p0300. Multiple missfire . think I'll just replace all the coils. With its mileage it can't hurt.

bennuss

test the coils for their resistance and change the bad one. why waste money. The back coils sold at advance auto are the japanese oem ones. the front ones seem to be a cheaper one made in poland.

tcb_02_max

iTrader: (5)

If you are having any issues with non-responsive O2 sensors, especially if you believe them to be original, replace them (at least the upstream ones). O2 sensors have a lifetime of about 10 years/100k mi, so even without a code, I would replace them. The sensor performance does degrade over time: slower response, less accurate readings, etc. I am writing a paper on it for my master's degree, so I've had plenty of exposure to the topic.

cashman35173

I have to replace both Bank 1 o2 sensors. I know they are upstream and down stream but, are they right or left? Thanks in advance.

bennuss

http://www.google.com/imgres?imgurl=...9QEwAg&dur=413