I borrowed a Snap on MT2500, older scanner, someone I know had it just laying around not using it so decided to borrow it to scan and see why my ses light was on. Scanned it and showed knock sensor, (replaced both and harness), skip shift, but thats because I broke the wire to it reinstalling my trans, I fixed that too. Then p0300 came up, random multiple misfire. Recently replaced all plugs, and gaped them to .040". I cleared the codes, and no light right now. Messing with this scanner I saw it had misfire data in it. Kinda figured straight forward on what it is. When I went into that it was showing misfires on every cylinder. Now idk if I'm reading the scanner correctly or what. Anyone know a lot about these scanners??? If needed, I can make a video of the data also.

 

It is possible to have misfires recorded for all cylinders. Clear the codes and it will reset them then see what comes back.

 

Thanks, messing around with it last night I think I may have found the problem. Few months ago I replaced my knock sensors. Decided to check the bolts and I must and not tightened them enough (probably fear of breaking the manifold). I tightened them up and the misfire data shot wayyy down. So I'm going to go back over them this weekend and hopefully that fixes the problem. Emissions coming up soon

 

Spray some brake cleaner along the intake edges while watching your short term fuel trims if they start to go negative then you have a vacuum leak and need to replace the gaskets

 

Thanks ill try that too just to make sure.

 

ok been a while I tried looking at the fuel trims and they stayed negative.... should I replace the intake manifold gasket? and which gasket, they valley cover one or the one where you replace the gasket on the manifold it self to the heads???

 

How many threads are you going to start w/ the same issue????