Driving to the lake this weekend, the OD light started flashing at me. The truck would down shift also. Shutting the engine off and restarting seemed to temporarily fix the situation. This problem kept happening and on the way home the transmision completely shifted out of over drive and felt as down shifted all the way to 3rd. Testing revealed that it seemed to shift fine from a dead stop all the way to 3rd. The fluid appears to be fine to me. To me this sounds as if it could be electrical. Reading on a separate thread I read that a dirty Mass Air Flow sensor could affect this. My check engine light has been on for a couple of weeks and it keeps reading 171 and 174, system to lean in both zones. I have read that this problem could be caused by a dirty MAF. Does it sound as if the problems are related? Can the MAF affect the transmision so much?

 

The truck is a 97 F-150, 4.6ltr v-8, obviously an auto tranny.

 

Check for vacuum leaks - pay particular attention to the PCV hose elbow. Lots of posts in the engine section about this, you need to fix and clear engine codes before worrying about the transmission.

 

The engine is not running noticably defficient. A slight knock at high rpm's has developed. I am thinking with the codes, and this, MAF.

My question is, can a faulty MAF affect transmission performance?

 

Clean your MAF, it's easy enough - but I'm betting that will not fix those codes.

 

Same Thing Happend To My 95 Turned Out To Be A Fuse