Project Sierra; Codes 33 & 45?

[kzvwrld]

About two months ago i bought a $1500 94 Sierra off marketplace, and finally decided to tackle the service engine light. Its been throwing codes 33 and 45 ever since I bought it. Started with the basics (cap and rotor, plugs and wires, fuel filter) along with a new battery, alternator and serpentine belt.

Now for code 33 I went ahead and just ordered a new map sensor. When replacing it, I found that the vacuum line was not hooked up to the rear of my tbi, and instead there was a vacuum cap on the rear port. My problem now is that after hooking up the map vacuum line to my tbi, i've had it stall on me twice after driving for just a couple minutes. Rough idle, loss of power, popping from exhaust (misfire?) its basically just not running correctly. I currently have the old map plugged in with the vacuum hose just pointed away and the rear port capped, and its back to running just fine again.

Any ideas why it would run better with no vacuum to the map? Could there be a leak in the hose? I was planning on ordering replacement vacuum lines soon.

On another note I currently have Bosch platinum plugs, but after some research i’ve seen many people not recommend them and even say brand new ones can cause more issues on our 305’s. should i replace these too?

Thank y’all

 

[Schurkey]

Plug the MAP sensor in properly, disconnect the battery for fifteen seconds. Reconnect battery. That will clear your codes, re-set your fuel trims, and likely eliminate Code 33 (low vacuum) and 45 (Rich exhaust.) Drive it and see what happens. If you still have stalling problems, connect a scan tool and verify EVERY sensor and computer output. See if any codes came back.

How old are the cap, rotor, plug wires?