jmb614

I have gone 'round and 'round with this 'set' of codes, having replaced primary O2 sensors at least twice in the last two years trying both Bosch 16272 and NTK sensors (current) to resolve the issue. These codes usually come together, and occur randomly, sometimes I won't see them for a few months, sometimes twice a month. I've also had a bit of a lumpy idle, especially at cold startup. Recently I changed the plugs and wires and immediately after began getting misfire codes and LTFT's went off the scale and AFR's at idle were around 10. After driving it around for about 20 miles the EGT's finally crept back up to normal and the AFR's evened out and the car began driving normally again.

I cleared the misfire codes and went on my way. A month later the P0130/P0150 codes came back, and the idle is noticeably different the moment the code popped. It seems as if the O2 sensors get temporarily fouled and the ECU doesn't know how to fuel the car so perhaps it reverts to a 'safe' map?

I guess I really just don't know where to go from here. Any others have this issue, and have you been able to resolve it?

jmb614

This time I did not clear the codes as o2 sensor voltages were swinging normally when the codes popped. I went through a few drive cycles and the codes and CEL went away on their own, I'm guessing my theory that the sensors get temporarily fouled could be the case?

At any rate, I will likely have the part-throttle maps checked/re-tuned.