mark weldy

2001 5.3l 2wd

bought it used from private seller. instrument cluster didnt work and was sluggish during test drive.

next day bought a BT ODB scanner, when i plugged it in the gauges worked(not fuel or oil PSI) removed scanner and gauges died again.
codes were:
p0304
po332
po354
po449
po452

these codes disappeared on their own a few days later
po300
po356
and two o2 sensor codes


replaced spark plugs, COP, plug wires and still have misfire.

Now here is a kicker. also have a parasitic battery drain, intermittently. just whenever it feels like it. could happen 4 days in a row, or could go 3 weeks without it happening.

im thinking PCM???

KChevy75

I'd focus on p0354 first as it seems to indicate the coil is either bad of something is wrong with the wiring. Swap the #4 coil with a different one and see if the misfire and coil code stay on cylinder #4 or move to the cylinder where you moved the coil. If it stays with #4, check the harness feeding the coil. If it moved to the other cylinder, the coil is bad and needs to be replaced.

Also, if the plugs and wires are old, I'd replace them anyway as part of routine maintenance.

Check for codes after the above is complete.

For the cluster, check all the fuses and check for damaged wires under the dash. This is an indication of a bad ground to the cluster. Could be the connector or wiring to the connector. Also check the ground strap that connects to the back of the engine on the passenger side.

The p0449 is an evap leak and p0452 is fuel tank pressure sensor related. The ftps could be a bad sensor, bad wiring or pcm.

I'd check wiring to the PCM and grounds. Reseat the pcm connector as well.

Irish_alley

im going to suggest clearing the codes and swapping coil 4 with another coil and seeing if the issue changes (i.e. changes to the swapped cylinder or goes away). if it swaps to the new cylinder then replace the coil. the evac codes are common and you can try to clean the evap canister or replace it. not sure on the pressure sensor

mark weldy

Thanks guys,

I bought all new coils,plugs and wires.

ive swapped all of those with other cylinders and still same issue.


the cluster comes on(minus fuel and oil psi gauges) when i plug in my bluetooth scanner. remove scanner and cluster goes out again.


im down to either PCM or coil pack harness

mark weldy

im buying a new locking gas cap today, just to see if that helps with EVAP at all

KChevy75

Check your grounds. I've heard of the "cluster only works when obdII plugged in" issue many times and it has always been a bad ground. Same thing with your misfires. Check and clean/derust any grounds connected to the engine.