Hello all. I have a 92 F150 with the 4.9 Inline 6. I replaced the computer a few weeks ago. Since then it's been having other issues it wasn't having before. It has a high idle. It seems to be running rich enough that you can smell it. It bogs down in high gears at speeds it didn't before. And it is starting to skip every now and then. I did a self check for the check engine light that's also been on since I replaced the computer and, if I read them right, it reads MAP sensor out of spec and clutch position sensor fault. But I'm not sure at all if I read them right. I'm at a loss. Any suggestions? Thanks

 

"MAP sensor out of spec and clutch position sensor fault." Some parts houses will pull the codes for free and you can verify the codes. Once verified you know what to fix.

 

Bad MAP sensor could make it run rich.

Not many parts places will pull OBD-I codes. You can by an Innova code reader for about $20 though. It's easier to use than the paperclip / count flashes method.

 

I did buy the code reader and it shows MAP out of spec but it also read vehicle not in park or neutral while testing but it was?

 

Is it a 5 speed or auto?

 

It's a 5 speed

 

Gotcha. Don't worry about the park or break code, either you've messed with the clutch switch or the clutch switch isn't working. This has no effect on drivability.

MAP sensor seems like the culprit. If you get on the 87-96 forum you'll probably find more info. But in general, if MAP is bad the computer defaults to a base programming for A/F ratio and (I believe) doesn't enter closed-loop. The MAP input, along with throttle position sensor and temperature sensor, are your main sensor inputs that the computer uses.