I just got this thing and bubba and his cousin been under the hood splicing and bypassing. I have several codes and I'm trying to fix one at a time. My question is when the truck is in park it runs strong hit the gas it goes great. When I put it in drive it does ok for the first 1/2 of gas pedal but after that it sputters and back fires. If I stomp on it its also fine. Codes Are 14,15,21,32,37,45,51,and 52

egr is bypassed, no o2 sensors, fog lights hooked into wipers (seriously) looks like they add a trans cooler and by passed the one in the radiator

1995 5.9 4x4 standard cab

 

14 MAP sensor voltage output is outside the acceptable range.
15 No signal received from the vehicle speed sensor during road load operation.
21 O2 sensor does not detect rich or lean condition,
32 Short or open in the EGR solenoid circuit.
37 Open or short in CKT wiring or connectors. Voltage out of range at transmission temperature sensor input.
45 Transmission OD solenoid circuit failure. Open or short in the transmission overdrive solenoid circuit.
51 O2 sensor signal indicates lean air/fuel ratio during engine operation.
52 O2 sensor signal indicates rich air/fuel ratio during engine operation.

Looks like you can fix several of them just putting the O2 sensor back in, and hooking it up.

Check wiring for MAP sensor. (on front of throttle body) If wiring is good, and you get the correct voltage to it, replace it.

Check the speed sensor on the output shaft of the t-case. Make sure it is plugged in, and getting the correct voltage.

Is the EGR solenoid just unplugged? Still hooked to valve?

Grab the 95 service manual from the faq section here. Wiring diagrams, and some troubleshooting hints are in there.

 

If it messes up in drive, travel in reverse.

 

Well I replaced the erg valve and now I'm down to 4 codes, truck runs like a champ. I noticed the map sensor didn't have the torque head screws in it, it was just held in place by the vacuum line!! I'm still getting 31,32,37,45 the bubba twins ran straight pipe so there is no o2 sensor. I did find the harness when I was under it. The overdrive switch in the dash is gone so I'm thinking that's what the code 45 is, I can tell the tranny has been replaced but the one in here doesn't have reverse so I guess I haffa get another one. There is also another wiring harness hanging by the tranny I think it may be what the 37 code is for