osuhog

iTrader: (16)

I can actually feel the lean-rich, lean-rich, lean-rich transitions as my 02's are switching in closed loop. I can see my wideband gauge bouncing quickly between low 14's/mid 15's & the car very slightly pulsates under part throttle.

As soon as I force OL in the scanner, the car runs perfectly smooth & my wideband gauge stays right at commanded afr without all the bouncing back & forth. Is this normal? Can anybody else actually feel the 02's at work?

ctd

iTrader: (1)

Is there specific rpm when you notice this?

Mine was very light load @ lower RPM. I was able to run slightly richer by adjusting the o2 switching voltage in the modes were the surge or pulse was occurring.

kobraa

iTrader: (1)

I have this same problem...car pulsates right between 2500-4000rmp range. I replaced the harness and I still have the problem. Any ideas? Maybe its the PCM?

cyipher

iTrader: (1)

I feel mine, Think its normal... But IDK?

02camarom6

I'm also having the same problem! my car is pulsating between 300rpm and 1700 rpm and it keeps throwing p1133 and p1153 codes. I talked with a mechanic who used to work at a Chevrolet dealership and he said the the IAC (idle air control) motor can cause it to fluctuate because it its not reacting to the signals the pcm is sending it and allow more air in than needed therefor throwing the codes! is there any truth to this?

30thblackcam

iTrader: (2)

Do you use HP Tuners? If so how did you do this and know which numbers to use? Trying to figure out this problem on a friends car.

JoshuaGrooms83

iTrader: (2)

this sounds kinda like what my cars doing but i wasnt thinking about the o2s and the iac's. my cars running weird latly and its gotten worse. ill have to check that out.