Popped her in the shop today...uh-oh....

[nodd89]

So with the truck running a little funny I took it to the shop and got them to do a cylinder contribution test and cylinder 8 had a code... While it was in there the tech reflashed the PCM, now he reflashed it to 99 programming (just cause mines a 99) but the po put in a computer from a 01 dOes that defea the whole purpose of having a 01 PCM? Also it had a code for a intake heater issue but im pretty sure e99 didn't have an intake heater....

Next step is to obviously check #8 injectOr... What's the best way pull the valve cover off and look for the oil squirting?

[audiocontr]

Very much doubt your #8 is bad. the new gray CPS cause scanners to trigger on cyl 8 yet they are well within their working parameters. Check change in rotational velocity of #8 (and #3). Youre fine if its below 10%.

I would think the PCM needs the appropriate firmware for the PCM code and not the year of the vehicle. Then again, a compatible PCM should have been installed in the first place. putting an 01 PCM in a 99 could cause lots of compatibility issues, then again, it could be a perfect match. too many variables and uncertainties.

[nodd89]

I took it in because of a low engine speed shutter

[audiocontr]

That could be old oil, bad gas, time for a filter change. Lots of little things could cause that. Is it a big deal or just something that only you notices because you know the vehicle so well?

You could have a bad #8 cyl, but i dont think you do and until the problem gets so bad it causes other codes, i wouldnt worry about it.

One thing i would do though is add a fuel pressure gauge. Fuel pressure is not monitored and its very important

[nodd89]

Low rpm shutter under load back off throttle goes away..the tech mentioned the cps may be throwing the code and make it run ****ty