bwhntr1953

Ok. Scanned my truck and got the following codes P0106 and P0107. Changed the manifold absolute pressure sensor. Re-scanned and I am still getting the same codes. Tried clearing the codes. Still getting the same codes. Now I don't know what to do.
Thanks,
Bwhntr1953

Gumby22

If you’re still needing an answer….

1) Depending on how you tried clearing the codes, they will remain stored in the PCM. Cheaper aftermarket code readers will usually only clear active faults but they won’t clear the codes stored in the history database. Read the manual for your code reader to determine its capabilities.

On a related note, I’ve recently learned that aftermarket code readers will not always display the complete list of codes for varying reasons, so it’s possible you’re not getting all the codes related to the problem.

2) There’s a number of causes for these codes, but the focus needs to be on P0107 because the cause of that code can also set the P0106. The MAP sensor uses a 5 volt reference from the PCM to generate a signal based on engine speed and load. I don’t know the wire colors off hand but at key on, engine off, there should be one wire with 5 volts (reference), one with 0.3 volts or less (sensor ground) and one with approximately 0.5 volts (signal wire).

3) If the wiring checks out, the most likely cause of the codes is a vacuum leak.

bwhntr1953

Thanks for the reply. My truck was also idling fairly rough so I have replaced the air filter and replaced the mass airflow sensor. This helped with the idling but of course course
the MAPS codes are still there. When I do clear the codes on the scanner the codes do remain. I've checked hoses for vacuum leaks and haven't found any. On another note, after changing the oil and filter now I get the P0522 code. Oil level is good occasionally the engine oil light will come on then go out. This is one big puzzle.

Gumby22

The intake manifold gaskets are known for leaks above 60k - there have also been some of the intake assemblies that crack.

Use carb cleaner on the exterior intake-to-head seams with the engine idling and up to operating temperature. Use a handheld propane torch to feed gas to the interior seams with a length of hose the appropriate diameter for your torch head.

An increase in engine speed from either test indicates leaking intake gaskets or a crack.

For more accurate results, plug all external vacuum feeds (brake booster, PCV, EGR, etc) to eliminate false positives from other systems/components.

The oil PSI sensors are known for problems as well. They work on the same 5 volt reference principle as the MAP sensor. It’s located behind the intake manifold against the firewall, so if you find yourself pulling the intake manifold, it’s a great time to replace it (if suspect) and inspect/clean/repair the connections in that area as well.