2009 G6, 2.4l, runs but bogs when acceleration
Hi! I hope someone can help me figure out this G6's acceleration issue. It bogs down as soon as you give it some pedal. If you just "feather" the pedal, barely push it down, it will go, just wont go fast at all. Slow. And as soon as you go to far with the pedal, it bogs down, just revs up and dont go!
Codes are, in this order, P0300, P0420, P0171.
I've checked all 4 coils, theyre at like 10.08, 10.01, etc. All 4 are good I feel. And the plugs are the GM factory still, the AC delcos that came with the car. No oil in the spark plug tubes and the engine is super clean! No leaks of any fluids over the years(yet), no valve cover gasket "fur" or oil seepage.
Then I checked the throttle body- Butterfly is shiny gold, super clean, all intact, wires tight and no fraying anywhere. When I open the tb and look in there, at the bottom of the intake theres liguid. You can see it fine but it's blackish, dark, so wondering if it's unburned fuel, coolant, etc. Not sure what it is yet.
The fuel pressure showed 58-60 psi. The injectors were all intact and nice and tight. No frayed wires at pigtails or anything noticeable just looking and feeling them. I did'nt use the noid or any checks but I feel theyre good. It starts right up, you can drive it, it's just that if you want to go over 30 or 40, that might take some time to get it there! Def dont try to get on the freeway!
The last few details are these(i'm going to try to write em all real short so this post isnt soooo long, Sorry!)
Compression- all 4 are at 91, 98, 95, 93.
air filter- new
terminals- 1 new 1 just fine
CATALYTIC Converter- checked temp with my cheap laser tempo thing from HF, got it like 2 years ago, 30 bucks I think, anyway, those temps were 220+/- before the cat and 110+/- after the cat. I held the red light on the edge of the cat on both sides of it. Not on the exhaust pipe before and after.
O2 sensors had a up and down on bank 1, form all way at the top of the graph to the bottom of the graph as it went, and was a steady up and down(not sure the numbers, I prob could've used a diff type of graph setting), the other sensor had a straight line, like no up and down the graph, just straight across the screen. Barely fluctuating at all.
I know this was lot of info at one time but I didn't know if I should try to send it in separate posts or all in one. Sorry if I over loaded ya!
Thanks for any input into this situation. I appreciate it she will appreciate it even more if I could somehow get it to accelerate correctly! I'm going to get the loaner tool for the head gasket check I guess next, or wait to see if you can direct me other directions. THX again!