Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
2003 Ford Expedition 5.4 p0171
- Thatboiiharris
- Topic Author
- Offline
- New Member
Less
More
- Posts: 9
- Thank you received: 1
3 years 9 months ago #41022
by Thatboiiharris
2003 Ford Expedition 5.4 p0171 was created by Thatboiiharris
Smoke tested already I couldn’t find any leaks other than the idle air control valve which has been replaced new iac still seems to have smoke coming from it I’m guessing it’s normal and swapped both 02 sensors from bank to bank still no change
Please Log in or Create an account to join the conversation.
- Thatboiiharris
- Topic Author
- Offline
- New Member
Less
More
- Posts: 9
- Thank you received: 1
3 years 9 months ago #41023
by Thatboiiharris
Replied by Thatboiiharris on topic 2003 Ford Expedition 5.4 p0171
Also put a vacuum guage to it got 20inhg and pinched off brake booster
And used a known good maf still no change in fuel trims
And used a known good maf still no change in fuel trims
Please Log in or Create an account to join the conversation.
3 years 9 months ago #41033
by Cheryl
Replied by Cheryl on topic 2003 Ford Expedition 5.4 p0171
Possibly a restricted cat because one bank is lean and one is rich. Have you checked fuel injector flow rates bank to bank
Please Log in or Create an account to join the conversation.
- Thatboiiharris
- Topic Author
- Offline
- New Member
Less
More
- Posts: 9
- Thank you received: 1
3 years 9 months ago #41036
by Thatboiiharris
Replied by Thatboiiharris on topic 2003 Ford Expedition 5.4 p0171
I did an injector balance test all of them drop 13 to 15 psi each
Please Log in or Create an account to join the conversation.
3 years 9 months ago #41038
by Cheryl
Replied by Cheryl on topic 2003 Ford Expedition 5.4 p0171
Did you check for an exhaust restriction?? With one bank rich and one lean I’d suspect it
Please Log in or Create an account to join the conversation.
- Thatboiiharris
- Topic Author
- Offline
- New Member
Less
More
- Posts: 9
- Thank you received: 1
3 years 9 months ago #41123
by Thatboiiharris
Replied by Thatboiiharris on topic 2003 Ford Expedition 5.4 p0171
I did a vacuum test since I don’t have a back pressure tester it had 21inhg of vacuum at 2500 rpm
Please Log in or Create an account to join the conversation.
3 years 9 months ago #41126
by Cheryl
Replied by Cheryl on topic 2003 Ford Expedition 5.4 p0171
Any TSBs? How’s it drive low on power??
Please Log in or Create an account to join the conversation.
Time to create page: 0.259 seconds