Engine light

[liljerryjr]

Engine light bank 1 bank 2 lean. Truck runs good. Replaced ox sensers an map senser . light still on .replace gas cap.light still on. Replaced hoses. What next? Light on for a year now.

 

[Bedrck47]

WOW you been a member since May of 2012 5 years and this is your first post and your light has been on for a YEAR NOW

First What took you so long to ask for help Seems to me that your not in any hurry to get it fixed

Second it would be nice to know what year expy you have

Third What are the code/s that you are getting?

Fourth Why did you replace the " ox sensers an map senser"

Fifth What other troubleshooting have you done.

 

[stamp11127]

Sounds like he is tossing parts instead of diagnosing the problem.
Lean on both banks means intake and/or gaskets are letting too much air into the engine.

 

[liljerryjr]

Po 171 po 174 2001 expedition runs good starts good. Idle good. But has lean codes. 5.4 egr good.pcv good. Somebody told me maybe fuel pump gasket leak? New gas cap.

 

[liljerryjr]

181000 miles on it.

 

[liljerryjr]

Maybe DPFB?

 

[Bedrck47]

Look at post #6 in the attached link for some information on your problem

http://www.expeditionforum.com/threads/p0171-p0174.32156/

What is DPFD or did you mean DPFE

Also read this attached link

http://www.expeditionforum.com/threads/about-egr-pcv-dpff-evap-iat-tps-maf.23583/

 

[liljerryjr]

DPFE controls EGR valve. 2 black hoses on it. Heard it can do this.

 

[Bruce Mitchell]

I had Check Engine light for bank 1 & bank 2 too lean. Replaced fuel filter - cleared codes & reset CEL; 3K miles since repair and no recurrence...

1999 EB 5.4 w/228K miles, BTW.

 

[Bedrck47]

I had Check Engine light for bank 1 & bank 2 too lean. Replaced fuel filter - cleared codes & reset CEL; 3K miles since repair and no recurrence...

1999 EB 5.4 w/228K miles, BTW.

Most likely you were lucky that is was something simple. Many other things can cause the same problem.

How long was the filter in the fuel line??

 

[drewactual]

if suggestions north of this post ^ fail, and after testing fuel pressure at the rail, consider either using a snap on to exercise the injectors individually, ensuring they work, or swap injectors odd bank to even bank, then monitor lambda on a reader. you can get a bluetooth dongle for >$10 (recommend elm 327) and download 'torquey' on a smart phone for free, which will allow you to monitor STFT/LTFT and lambda- pay attention to the STFT alterations. realize: the sensor data is NOT raw- the PCM data displayed is what the PCM is doing about the situation... example: a STFT showing +10% demonstrates a LEAN condition NOT a RICH- the adding of 10% pulse is to combat the lean... a -10% is a RICH condition, and the PCM is pulling fuel to combat it.

if you touched the o2 sensor to any kind of glycol (antifreeze) it's toast... gotta get a new one.

if the sensor (o2) is good it can only read what is happening... an exhaust leak or vacuum leak (un-metered air) can cause same reading. make sure those are addressed.

a clogged basket on one of the injectors could cause the reading as the PCM doesn't trim pulse on individual injectors- a bank (4 cylinders on a v8) is as close as it can get... one bad or partially clogged injector can do this. if the cylinders were any easier to access, i'd rec you get a scope and get a look at the walls- comparing them.. another and much easier way is to simply pull the odd bank spark plugs and compare them against a chart (google for one). you should be able to discover a lean cylinder quickly doing that. if it's proven lean, you hafta figure out why.