help!! p0300 misfire, tps fault, bank 1 and 2 lean fuel trims...

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

xps800doo

TYF Newbie
Joined
Sep 17, 2021
Posts
1
Reaction score
0
july of 21 purchased a 08 with 170,***. seemed fine had a rough idle never put a scanner on it to look at anything, then started throwing a throttle body circuit a fault, ordered a oem throttle body sensor new plugs and wire just because, put them on the shelf for then I have time. 12/21 flashing check engine light along with stabilitrac and traction control lights. put the scanner on it and strong #6 misfire, pull valve cover rocker loose.... tore into it. replaced all rockers, trays, had heads gone through, new VLOM, new oil pressure sensor....now i am getting a cyl 1 & 7 misfire at idle only, as soon as you raise it to above 800 rpm the misfire goes away. getting a p0300 misfire still getting the throttle body sensor fault, bank 1 and 2 fuel trim lean fault. and low oil pressure fault.

the gauge was at 40 almost all the time before #6 failure, now it will go to 40 at start up and after a few seconds drop all the way to 0. Rev up engine and it will come back a little… don’t have a pressure gauge, but there is some oil there, been driving it a week now .

Tried the carb clean spray trick around the intake and injectors and that doesn’t seem to change anything.

Where does one go from here!?
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,482
Reaction score
39,840
Location
Stockton, Ca.
oil pressure is probably the pickup tube o-ring, very common
have you cleaned or checked the maf?
 

AmunRoo

Member
Joined
Dec 27, 2021
Posts
66
Reaction score
82
Location
Chicago
You should try a leak down test on the cylinders. Have you tried a compression test yet?
 

Foggy

Full Access Member
Joined
Jul 25, 2019
Posts
1,106
Reaction score
1,425
Location
KS
Common for #6 to misfire the most when plugs/wires are going bad..
Replace that easy stuff first.... then go deeper if it doesn't help..
Just went thru this with a 1500 that only had 30K on the plugs and wires
 

Russ

TYF Newbie
Joined
Feb 28, 2015
Posts
16
Reaction score
2
My first concern would be to verify proper oil pressure. Have you inspected the screen under the pressure sending unit?
 

Forum statistics

Threads
132,705
Posts
1,872,885
Members
97,521
Latest member
Chaos49090

Latest posts

Top