EEC Codes 81 and 41 MAP Sensor vacuum line?

[mholhut]

1991 SHO, EGR removed / PCM swap. New intake runner couplers, replaced entire set of intake gaskets... secondaries, the whole nine yards. New plugs, wires, coil.

Runs decent, no bottom end power in 1st gear, seems like secondaries don't open (can't hear of feel them open). Still need to change the O2 sensors (have them, going in tonight.)

After 10 minutes of running, CEL comes on. Codes are 81 (MAP Sensor?) and 41 (O2 sensor?) Knew the car was running lean, so the O@'s will be swapped tonight. MAP sensor is odd. Looked at mine (if I'm looking at the right component, firewall, just below the cowl vent - passenger wiper area) and it looks like there's supposed to be a vacuum line attached to the MAP sensor... mine just has a gray plastic cap that has a hole in it that does apparently nothing. I have no idea what vacuum line goes to it at all.

Any ideas????

-Mike

 

[shobote]

Um if you have a Gen I or II, it does not have a MAP sensor. Someone else can chip in who knows the codes. SHO's use MAF sensors, which are on the intake between the TB and the air filter. The O2 sensors would not just go bad suddenly. IF it ran fine before you swapped parts out, it has something to do with your efforts. Check all the vac lines, as one may have cracked when you removed the intake, if you did not put on new ones. Make sure the clamps on all couplers are tight.

 

[mholhut]

K, We have a BAP and that's not where the code came from... looks like the 81 code is for the IAS... explains the secondaries not opening. Autozone doesn't list an Inlet Air Solenoid... and I guess it's called the IMRC now (like the Gen III's) Anyone else sell them???

O2's have been bad for a while... need to be changed. Whole car was on it's death bed in the Spring so I let it sit all year. Just trying to get it running now before the snow flies.

 

[mholhut]

Yeah... I'm a douche. Forgot to plug in the IMRC or IAS when I put the manifold back on. Case closed.