[TXC]

Is this issue the running of the engine? as in, if you get it up to temp it runs awful even when stationary in Neutral?

Disconnecting Temp Sensor resolves issue virtually entirley?

I'm just thinking, by disconnecting the sensor, the car sees infinte resistance or open circuit, so therefore thinks -35 C, yes, you already know that. You are 'telling' the car it's colder, and it is, so....

The car never reaches 'closed loop' because it never sees the correct figure, lets say 65 C for fun.

Without 'closed loop' , it'll never listen to the H02 sensor (Lambda, whatver name you prefer).

I'm thinking if this sensor is stuck 'lean' for example, as soon as we hit 65 C, ECU starts to listen, finds it lean, winds the fuel right up to try and get the sensor to switch correctly, it never switches or responds so the ECU just keeps the fuel addative on max.

Same principles would apply if the sensor is stuck rich, so it would try leaning it off etc Same result, rough running.

A covoluted way of explaining that I don't think its hitting closed loop with the Coolant sensor off, and a duff HO2 sensor would give all these rough running symptoms.

Will not always leave a code, however you can test the HO2 sensor (I'll assume it's a four wire for now), either backprobe the signal wire and get it up to temp, monitor it.
Or if you have live data on your Autel, use that to give you feedback.

Cruising at 70mph may well mask a stuck rich/lean sensor, in fact at higher engine speeds the sensor may begin to switch nicely, then fail miserably with lower gas content to sniff.

Best of all, it's free to test.

Although it would throw a code (which you can clear of course), there's nothing to stop you just disconnecting the HO2 sensor so that signal never gets back to ECU, it may not run perfect like this, but it may prove the point crudley but effectively.


Sorry for essay, but i had to explain as best as poss without confusion, dunno if it worked though lol.

I know you are also concerend about the Autobox, but the crank speed will be slowing down and speeding up randomly on misfire, affecting the shaft speeds, and confusing the box whats being asked of it.