mytrplseven

I saw some posted info that some 944's are running with the O2 sensor disconnected. In an effort to force my 944 n/a to run richer, I disconnected mine and the car ran great.....however, the idle cycled between 200 and 300 rpm. It's especially bad with the A/C on. I have a new O2 sensor and Cat.

If some of you are doing this, are you just living with the dreadful idle or have you found a way to avoid it?

mytrplseven

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V2Rocket

200-300rpm?
The car should barely run if at all at 200rpm.
Have you adjusted the throttle stop?

mytrplseven

No, I meant that the idle cycled that much but target idle was around 900 rpm.

odonnell

My car idles the same whether or not it's plugged in.

mhr

On my S2 mine was accidentally disconnected and the warm idle was terrible. Same thing up and down about 300 rpm.

konakat

It shouldn't make a difference. Chances are the O2 sensor was masking another issue. Better to find that issue than to reconnect the O2 and pretend it isn't there.

Dimi 944

I have been running without an O2 sensor on both my 2.5L and 3.0L engines with no issues once the car warms up.

mytrplseven

That's what I've been doing for the last year. The car runs lean after warm up and at WOT it goes like stink and idles great, but normal acceleration it hesitates. I won't bore anyone with the list of the components I've changed or swapped, but safe to say the only thing left is the short block.

austin944

I had similar symptoms after a shop did the clutch on my car. It was like driving a turbo with a lot of boost lag -- very poor acceleration off the line but once the RPMs spooled up, it was really fast. For some reason, the mechanic had inadvertently knocked the j-boot loose from the air-flow meter. After re-connecting it, the car was back to normal.

mytrplseven

You know, that's interesting....I've had my j-boot off several times and even though there's no cracks I did notice the lower lip had been crushed when the boot was previously installed on the throttle body. A possibilty since it's almost impossible to see when it's clamped down. I'm now wondering if I might have a vacuum leak there causing the lean mixture issue I've been chasing.

Sounds like your mechanic may have jacked the motor up a little to align the spined shaft of the torque tube to get a final fit into the clutch and engine. I had to do that when I did a clutch job. That would explain how the J-boot might have gotten disconncted from the AFM.