Bad Oxygen Sensor or Something Else?

[duke52]

Alright guys this is strange.

I'm logging o2 values, airflow rate, and timing, on my 99gst and following my egt's with a gauge. The car seemed to fall on its face @ around 5500 rpms so i took some advice and started logging my airflow rate and found that it starts to fall at about 5500 w/ my br20g? anyways at this point the logger says it goes rediculously lean! i mean not possible lean. The o2 values are like .12v yeah, however it's not pulling timing and the egt's are around 1450 f. The o2 sensor is about 2 years old, and i had been running really rich untill recently when i bought and installed a afpr. did the o2 go bad or is it possibly my ecu or something like that? the o2 seems to work until open loop,
thanks in advance

 

[scottsee]

dead or slow o2 will make all the ecu trim levels high! giving you that lean condition your talking about. also during idle or low throddle position and low boost your o2 should cycle up and down between .2v to .8v. if it dosent, bad o2. leave your car at
leave your car at idle for 5 mins and see if the o2 stop cycling, if they do, bad o2.

buy a wideband, no better time then now. gota go under their anyway!!

check out www.pocketlogger.com good website for datalog tunning!