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Q: I have a bad idle and surging problem after it warms up. on 2003 Ford F-150

If I un plug the MAF it seems to clear up. Replaced MAF about 500 miles back. Replacing TPS and have replaced Vac sensors on EGR AND CANISTER vent valve.
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should have been 5000 miles, I'm checking on a smoke test to check for vacuum leak. Seems you can't do it with spray as the PCM will try to compensate it.

I don't know the system well enough to understand why unplugging the MAF would fix the problem.
I think your right on with the vacuum leak. I changed the TPS and drove for 40 minutes and no problem. I did get a rich burn code, cleared it and it did not come back. Will replace problem PCV hose on back of intake and drive again. Hope this is the vacuum problem.
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