Hey guys,

So I am trying to pin down the reason for my 4runner's horrible gas mileage, and am starting to think it has something to do with the TPS, but I am looking for some advice on my situation.

Lately I have been noticing that every once and a while my idle will drop from 800 rpm to around 200 rpm, the lights will dim and the oil pressure will drop off. My throttle response isnt ideal but its also not horrible.

All of that has led me to believe its a TPS issue, but before going in a testing the tps with my multimeter I wanted to just unplug the tps and see if anything changed. The result was a rise in idle and a little better throttle response and low end power (may just be the placebo effect), but the confusing part is that unplugging the TPS did not cause a CEL. Is this something that I should be worried about? I will be checking the resistances of the tps tonight to make sure they are in spec but I was quite surprised when I didnt trigger a CEL.

Any thoughts on this matter would be greatly appreciated.

Thanks

Most CEL codes are not instantaneous, the condition must exist a specific amount of time or cycles before a code is generated.

well I drove it around for the day unplugged and no cel ... I figured that should have triggered it

did it run better with the TPS unplugged?

its hard to tell. Really the only issue that was present while it was plugged in was really poor mileage and throttle response, and the idling wouldn't stay at 800 rpm. It ran fine though, no rough idle or surging while driving.

The throttle response seems a little better, and the idle stays pretty constant at about 1000 rpm, but thats about all that has changed.