'07 More issues

[Motorcity muscle]

Truck idling in park, idle at 500 rpm's, running rough. Speedometer was ranging between 10-20 mph. Never had this happen before, so I put it into gear and back to park and then things returned to normal, idle was 7 to 800 and smooth. Could this be related to vehicle speed sensor? No check engine light at this time but it did flash on and blink for a minute or so. Just changed plugs, a coil, drivers side cat and belt tensioner. Truck has 137,000 miles on it now.

 

[Motorcity muscle]

Never give up, 78 views no ideas, back to basics. Decided to start with simple, little humbling, changed the fuel filter and she is running much better. When I went to bleed off the fuel line pressure at port on engine, got some dirty fuel. Hope this helps others with troubleshooting. As far as replacing filter, never replaced one on fuel injection vehicle. The two lines on the one side of filter had blue fittings, had to pull out the center blue tab and then push in on the remaining tab to release lines. The outlet side had the regular slide in the tool to release line. Everything I looked at online did not have the center tab you pull the tab on and then push in to release line. Think this may have been the original filter on this truck because the hose clamp that holds the filter was facing upwards and difficult to get a 5/16" socket and ratchet on to loosen. Once it was loose was able to spin the hose clamp and remove.

 

[Motorcity muscle]

Got the truck running like new. Started to get a whistle under acceleration, no check light, low on power at top end. Had to replace the passenger side cat, again. Only two years old, dealer swapped it when I bought it couple years back when it set the check engine light the next day after buying it. Guess it's an expensive lesson if your getting missfires fix it, hope this helps somebody out.