I installed the new 02 sensor, but it didn't make any difference. The fault codes came back again. I've checked the AMM and the IAC-- everything checks out fine. As I was checking resistance on the control unit connector, I noticed that the readings were off on the TPS. The service manual says to co...

I went ahead and ordered a new O2 sensor, just in case my readings were wrong. It's probably due to be replaced anyway. Hopefully it will solve everything. Not sure if it will solve the missing signal to/from the IAC, but I will give your suggestions a try and post back. Thank you so much for all of...

I have LH 2.4

I already replaced the ECT.

Yes, unfortunately, they come right back.
thanks for your reply!

I'm hoping someone can help me with this... My 91 volvo 240 was having low idle issues on start up when it's cold. To try to fix the problem I cleaned the throttle body, cleaned the flame trap, replaced the idle control valve and the intake accordion hose. After that, the check engine light came on ...