My 1995 automatic transmission Buick lesabre with nearly 60k miles on it is getting a po341 and po342 trouble code (scanned with snap on MT2500). The car has a rough idle, misfires frequently, is a hard start, stalls at low speeds, has loss of engine power, and I find it difficult to get it up to higher speeds. What I have done so far: Replaced cam sensor (re-used OEM O-ring as well), replaced ICM, replaced PCM, replaced coil packs, replaced wiring harness, checked grounds underneath ICM block, and checked to make sure my cam magnet was still intact (it was). This one really has me scratching my head so any help is greatly appreciated, thank you.
Have you checked engine compression just to be sure you're not fighting an internal engine problem?
1995 would be a transition year just before OBD2 was fully implemented and I'm not sure how deep you can go with that MT2500. You may need a GM Tech2 scan tool (which is what dealers used) for a full electronic diagnosis.
try the troubleshooting here
https://www.obd-codes.com/p0341
If you can get your hands on a multimeter with frequency function, or better yet a scope, you can test for signal that way.
according to GM, P0342 is not a valid code for the 3.8L engine in that year.
https://gsitlc.ext.gm.com/gmspo/mode6/pdf/1995/95c38k_F__aE.pdf
