partial throttle problem with check engine light

[bradranger]

I was at the track one night when my car all of a sudden popped on the check engine light. Nothing really changed in performance that night. But recently I've have had trouble with the rpm range of 2000-2500 in gear and sitting still in neutral. It does it when its cold and hot. Now the check engine light only comes on when the car is warmed up. The only thing I did before this started was that I installed a Accell coil and ignition box, but it ran fine for a week with it on. I did unhook the ignition box and still had the same problem. I have a brand new set of ford racing wires 9mm and autolite plugs. Any suggestions would be helpful. I will be running a code scan on it tommorow.

 

[PRO50SC]

You do need to find out what code you're setting. What year Stang.
Possibilities, If this applies to your application, The egr position sensor will trip the light under light cruise accelleration as will the TPS. These are very common problems. I'm iterested to know what codes you have. I also live in Md.(Olney) to be exact. How about you. Send me an e-mail with your info and I'll get back to you.

 

[jrichker]

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

 

[bradranger]

I pulled the codes and I got 21,24,21,24,34,41,66,96,34,41,66,96. Disregard 66,96 I took the hose off the mass air meter and put it back on. Also I removed my smog pump recently. I replaced the engine coolant temp sensor so its not that. I do have a question, on the vaccum hoses where the egr and stuff go, the vaccum hose that went to the smog pump should I block these off, since I dont have nothing to hook it up to? But I did try to block these off and it ran the same. Just wondering if I should?

 

[schoonover_88]

I have heard that if you have an off-road x-pipe, or h-pipe and don't do something with the oxygen sensors that it drags down your performance. I don't know if you have an off-road pipe, but if you do this could be your problem.

 

[bradranger]

o2 problem

I changed out both o2 sensors and that cleared most of the problem, I still have a little hesitation around the 2000-2500 area, so I'm going to put new plugs on and see what that does. I let it run for about 20mins after I drove it and I have no more check engine light. Thanks for the help!