Clearing faults with durametric caused a surge at idle

[steved0x]

To follow up to this thread, my CEL has gone off and been off for over a 1,000 miles since this thread was started. The only thing that has changed was... I have moved to FL and I am getting gas at this one store that in my opinion has really good gas. When I would visit down here and fill up my FJ with this gas I could drive probably 30-40 miles further on my tank than I could if I filled up at other places. (I can't think of the brand of gas but I will drive by tomorrow and update the thread)

I didn't change that O2 sensor, clean the MAF, or do anything else.

I am about to change the oil, filters, plugs and plug tubes, and when I have the engine compartment open I will clean the MAF, but so far everything is going really good. Idle is rock steady, good power. I hate to say it, but I am thinking it may have been the Costco gas in NC that was giving my problems. I love Costco so I hate saying that...

Steve

[thom4782]

A dirty throttle body is a classic cause of a hunting or variable idle. You might give that a cleaning too while you're in the engine compartment.

A secondary air system leak might be the cause of the on again and off again CEL. it comes on in cold temperature conditions. If you're in FL, it might not start the secondary air pump. If enough good cycles go by, the CEL might think everything is working again.

All that said, I'd start along the lines you're planning. Clean everything. Clear all the codes and see what happens. If the idle is steady, the one problem solved. If you get a CEL again with an aging related code, the replace the aging part. Then get the secondary system leak tested.

Best of luck