E36 IAC?

[toomanycamaros]

@CJRando

The fuel pressure checked out. IN 1st gear the car revs up, but then it strains to build rpms, once it hits 4k, its like hitting a brick wall in any gear. I checked the new MAF, and its a cheap ebay one, so I’m going to go see BMW Joe tomorrow and swap one out and see if thats the issue. I replaced every vacuum line, to include the small on on the FPR, IAC hose, the elbow, CCV, and the IAC. I also reconnected the vacuum, under the fuse box, to the T fitting and replaced the canister just to be on the safe side for now. If I disconnect the MAF the idle will stumble a bit, but then no difference. If this is not the issue, I’ll probably take it and get the cat checked. I’ve only sunk $150 in misc parts so far, most of which is stuff which should be replaced reguardless of this issue.

Adam-- thanks for the info on the fuel pressure!

A low tech way to see if the cat is your problem would be to pull the upstream O2 sensor and see if it makes any difference.