Hi all, 1995 f150 5.0, mass air, 302, auto, 4x4. The check engine light is driving me insane. When I first start the truck it idles perfect and throttle up perfect. When I put it in drive and first head down the street, as soon as I let off the gas the check enging light comes on and then promptly goes off sometime 20 seconds to a minute later. It only comes on when I give quick or large amounts of input to the accelerator. In no way does the engine ever bog down or miss though. The light shuts off, would the code still be stored? Here is a list of replaced. items. Im beginning to think its a vacume line.
TPS, IAC, EGR With Solonoid.

Any thought please!!!

 

Stop throwing parts at it and check the codes.

 

those are parts that have been replaced before this issue within the last few years. Per the post above,"will the codes remain stored if the check engine light shuts off?" thanks!

 

I had a similar issue with my 93 F250 351W and until I checked the codes it drove me crazy. My codes did stay even though the light was not on. it was my fuel pressure regulator and when I would give it gas the passenger bank would run rich causing the codes.

 

Codes are stored to the computer even if the light is not on.