zeethreethree

2007 350z HR

When I got my car a little over a year ago it had codes being thrown for all the O2 sensors. Last week I finally found out that there was a fuse for these and replaced it. After replacing the fuse, the O2 sensor codes cleared up, but then I got a new idle code. I did the idle re-learn, and that code went away and hasn't come back.

The first time I drove the car after replacing the fuse and doing the idle re-learn was a couple of days later. It started and idled fine, got out of my parking lot fine, and then a couple hundred feet up the road the accelerator pedal stopped working while driving. I pulled over and put it in neutral, and the pedal wouldn't rev the engine. I turned the car off for a minute, then turned it back on and it would idle and rev in neutral okay. I got a tow back into my parking lot from there, and after coming down off the tow truck, the accelerator was still having issues. No check engine light or codes found.

Last night, I disconnected the battery and cleaned the posts and terminals and put all the cowl and trim back on from where I had taken them off to change the O2 sensor fuse. I turned the car on and it idled and rev'd fine for 10-15 minutes, then I drove it around inside my parking garage and it seemed fine. I went to take it out on the road, and the throttle stopped working again before I could get to the stop sign. Still no check engine light or codes. This time I got it towed out to a shop.

At the shop, I was able to drive it around to a bay, and it idle'd and rev'd fine for about an hour while it was hooked up to diagnostics, still no codes or CEL. Accelerator and throttle sensors seemed to be reacting normally at that time as shown on the reader in a voltage graph.

We took it out for a drive from the shop while hooked up to a reader, and the issue happened again. While the issue was going on, the accelerator sensors seemed to see the pressing of the accelerator, but there was no response on the throttle sensors 1 or 2 now.

I have also done the pedal position re-learn, throttle body closed position re-learn, and the idle air-relearn a few times, and it did not change the condition.


TLDR - throttle sensors 1 and 2 (and the throttle itself) are going non-responsive after driving and shifting for a couple of minutes, no codes or CEL thrown.

Has anybody seen this before? Any ideas?

zeethreethree

So an update on this. We hooked it up to an OBD reader and noticed the throttle position sensors weren't getting signal when the accelerator was being pressed any time the issue came up. The accelerator pedal itself seemed fine, so I got a pair of new throttle bodies. Put them on and still had the same issue. Ran a bunch of diagnostics on the throttle position sensors and accelerator sensors after that and they seemed okay at idle. Decided to try just taking the O2 sensor fuse back out, and the car works fine again. The throttle response is much better with the new throttle bodies when the O2 sensor fuse is in, but the car stops responding to throttle after just a couple minutes of driving. Thinking this might be a short in an O2 sensor or something since it only acts up when the O2 sensors have a working fuse. What's the best way to test the O2 sensors for something like this?