I have a 1997 F150, 5.4L, 4x4, with 114k miles. I just purchased it recently. It runs ok, check engine light is on, but misses/shudders a bit at higher speeds, especially when towing. CEL codes came up as O2 sensor slow response the first time, cleared codes, came up as "lean, bank one" the second time. I would like to do a complete tune-up on the truck and made a list of things to do. Does anybody else have other recommendations I have overlooked?

- change fuel filter
- clean injectors
- air cleaner
- oil/filter
- clean MAF sensor
- clean throttle body
- change plugs and COPs
- check all vacuum lines and replace
- replace pcv valve (don't get fram with small hole)
- tranny filter and fluid (and install drain plug in pan while down there)
- change transaxle fluid
- change differential fluid
- check/clean brakes

If after doing the above I still have a CEL, I'll likely replace the front O2 sensor. There is also a terrible buzzing sound under the hood that I ned to diagnose. It does not sound like a vacuum leak, although it continues for a split second after I shut the motor off, the way a vacuum leak does.

Finally, I have the problematic "blend door" problem so many others here have had. I have on my list to replace that, along with the heater core while I've got it apart.

Thanks for any input. This site is AMAZING!!!!

 

Hi.

Change the front O2's - both of them ( there are 4 total - it's the fronts that control A/F's), asap. They're done.

Also don't neglect EGR/DPFE in your R&R and cleaning of the TB area.

Brake fluid replacemnt might be good.

Check/replace the coolant / rad hoses ?

Good luck - quite a list.

 

Thanks MGD. Couple of questions though. What is "A/F"'s? I have not gone under the truck yet, but the guy at the parts store said the truck could have 2 O2 sensors, or 4. Does the 1997 F150 5.4L always have 4 total? (2 pre-cat, 2 post-cat)?

What is "DPFE"? I do know what EGR is, and think I saw some posts on cleaning those.

As for coolant and radiator hoses, that will get done when I do the blend door and heater core that I mentioned.

I just joined the site yesterday and even though I've been ready to sell the truck because it ran like c*r*a*p when I towed, I think it seems to be more of these quirky F150 things like vacuum leaks, COPs, etc. rather than a "you need a new tranny." So I think I'll keep it and give it a go.

 

Your EGR system -




I would do this as well -

http://www.fordf150.net/howto/throttlebodyclean.php


AND this too ( :

http://www.fordf150.net/howto/clean-...low-sensor.php

 

Hi. Sorry about the abbriviations lol.

A/F = air/fuel ratios - properly functioning 'fresh' O2's are critical to this control by the PCM. Almost positive you have 4. Approx $50-$60 each from AutoZone , etc - only get the Bosch ones ( which is Ford OEM anyway).

DPFE - look for posts by Jbrew, or plug DPFE into the search engine - which is your friend here lol. Short for Differential Pressure Feedback - EGR. It's the mechanism that regulates the EGR system and i crucial to driveability. Over time they can get bunged up - Jbrew is a wizard with this stuff and a lot more - his posts are awesome reading - a lot are in the Engine section.

(Also - quick Google works too - http://www.tomco-inc.com/Catalog/dpfe%20sensors.pdf)

Good luck.

 

That's a great diagram jbrew. I had seen the MAF sensor cleaning diagram and it is definitely on my list of things to do. I had not seen the TB cleaning thread so thanks a ton for that.

As for cleaning the EGR system/ports, is there a thread with diagrams for that as well around here? And for cleaning the DPFE sensor?

Once again, this place is amazing and you guys are a wealth of info.