Proper diagnostics
Thread Starter
|
Lead Driver
Joined: Mar 2006
Posts: 6,264
Likes: 438
From: IL
Proper diagnostics
Ok so my automotive knowledge is mostly in 1995 and older drivetrains, but my 03 F350 5.4L which sits the majority of the time was called to duty on Saturday to go pick up it's new bed. The engine is running rough, lack of power, feels like it's missing a cylinder. Hooked the scanner to it because no CEL is on,
My codes are P0303 and P0171 so misfire on #3 and Lean on bank one.
I popped the hood, removed air filter, a little dirty but passable, I sprayed the MAF with MAF cleaner.
I climbed on top, checked #3 COP and it's wiggling, I have not removed it, I really don't know what to expect when I do, but I do know that none of the other COPs are loose, so can I expect a bad Boot? Is it shot, am I probably looking at a busted spark plug?
Other than fixing #3 cyl problem, what other diagnostic steps should I take to fix these codes? I bought the truck 1.5 years ago, at 132K it now has 135K, I haven't done anything to the engine except an oil change and fixing the leaking trans cooler lines and power steering lines. All other work has been on the front diff and front driveshaft. and some light electrical. I have no maintenance history on it other than what I have done to it.
Thanks for any advice
My codes are P0303 and P0171 so misfire on #3 and Lean on bank one.
I popped the hood, removed air filter, a little dirty but passable, I sprayed the MAF with MAF cleaner.
I climbed on top, checked #3 COP and it's wiggling, I have not removed it, I really don't know what to expect when I do, but I do know that none of the other COPs are loose, so can I expect a bad Boot? Is it shot, am I probably looking at a busted spark plug?
Other than fixing #3 cyl problem, what other diagnostic steps should I take to fix these codes? I bought the truck 1.5 years ago, at 132K it now has 135K, I haven't done anything to the engine except an oil change and fixing the leaking trans cooler lines and power steering lines. All other work has been on the front diff and front driveshaft. and some light electrical. I have no maintenance history on it other than what I have done to it.
Thanks for any advice
Fleet Owner
Joined: Apr 2008
Posts: 24,323
Likes: 5,133
From: 0,0,1
None, fix the misfire and see if it takes care of both codes before you do anything else.
Thread Starter
|
Lead Driver
Joined: Mar 2006
Posts: 6,264
Likes: 438
From: IL
So the possible misfire on #3 could also cause the lean on bank 1 code? I would have thought the opposite, just because if it's not firing that raw fuel would be dumping into exhaust causing a too rich condition.
Hotshot
Joined: Jan 2004
Posts: 19,768
Likes: 1,082
From: St Louis
"Lean" codes to not mean the engine is running lean, they actually means the opposite. The fuel table have shifted to their maximum positive enrichment limit but the O2 sensors are still reporting the extra rich exhaust as "still too lean". Usually caused by too much un-metered air entering the system, other causes are indeed possible. A misfire dumps unburned fuel into the exhaust and can compound the issues.
Fix the misfire, reset the system and re-test. You may have multiple issues.
Fix the misfire, reset the system and re-test. You may have multiple issues.
Thread Starter
|
Lead Driver
Joined: Mar 2006
Posts: 6,264
Likes: 438
From: IL
that's what i thought also but i felt and its there so i sprayed pb blaster on all the cop bolts and ordered a couple of new ones from ford....they ain't cheap either...lol
Thread Starter
|
Lead Driver
Joined: Mar 2006
Posts: 6,264
Likes: 438
From: IL
New coil on #3 fixed it BUT...the po must have been in there before? The bolt is good but the hole os stripped.
Thread
Thread Starter
Forum
Replies
Last Post
dclack
1997 - 2006 Expedition & Navigator
14
Jun 20, 2022 09:38 AM
randy217
Explorer, Sport Trac, Mountaineer & Aviator
4
Jan 3, 2013 07:28 AM
