idling rough after a few days...
Thread Starter
Staging Lane
Joined: Jul 2003
Posts: 67
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idling rough after a few days... Okay, here is the situation. I have been running the engine now for a few days without any problems. This afternoon, when it was running for a while it started idling rough, it didn't stall but it seemed like it wanted too. I have the rear O2 sensors unhooked and the front are hooked into the manifolds. I have the OLD cataltyic converter on there still, but it was running fine up until today. What could my problem be? I don't have the diagnostic tool to check for codes yet. Is there anyway I can troubleshoot this thing? My fuel pressure is good, and I dont think that I have any vacuum leaks, but I am not sure. Any help would be great.... 
Shouldn't he be running O2 simulators on the rears instead of unhooking them? Unless the PCM has been reprogrammed to eliminate them, the computer is looking for a signal. Can someone confirm this?
Mark,
From what I know the rear O2 sensors are not needed at all with the right programming.. the front O2's are what the engine uses for engine management.. the back just check to make sure the cats are doing thier thing and throw an SES if there is a problem.
From what I know the rear O2 sensors are not needed at all with the right programming.. the front O2's are what the engine uses for engine management.. the back just check to make sure the cats are doing thier thing and throw an SES if there is a problem.
Unhooking the rear O2 sensors will set a code with the PCM, but it will not affect the way the engine runs. I had a problem with rough idle a few days after startup and it ended up being a vacuum line that comes out the back of the intake (not the brake booster).
Thread Starter
Staging Lane
Joined: Jul 2003
Posts: 67
Likes: 0
The idle starts to get rough when it gets hot. I only have one fan hooked up right now. I am going to go with two 14" fans rather than one 18" fan, hopefully this will get it cooler. As for the vacuum, I check and all looks good back there.
