code 171 + 174

[towiseman]

Hi
I have a 2001 e-150. I am having code 171 and 174 very often. I have changed the Mass airflow sensor DPFE, PCV valve, air filter, cleaned the idle valve but still I am getting the codes a few days after each change. Frame feeze data is
iNSTANCE 1 iNSTANCE 2
Eng spd 1033 1291
cALC. lOAD 44.7 69.4
cOOLANT 190 189
ST frame 1 3.1 5.5
LT frmae1 -3.9 7
ST frame 2 5.5 8.6
LT frame 2 8.6 14.1
Why I am getting 171 and 174 code all the time??
Thanks
Abe ([email protected])

[tempfixit]

Originally Posted by towiseman

Hi
I have a 2001 e-150. I am having code 171 and 174 very often. I have changed the Mass airflow sensor DPFE, PCV valve, air filter, cleaned the idle valve but still I am getting the codes a few days after each change. Frame feeze data is
iNSTANCE 1 iNSTANCE 2
Eng spd 1033 1291
cALC. lOAD 44.7 69.4
cOOLANT 190 189
ST frame 1 3.1 5.5
LT frmae1 -3.9 7
ST frame 2 5.5 8.6
LT frame 2 8.6 14.1
Why I am getting 171 and 174 code all the time??
Thanks
Abe ([email protected])

Have you done a smoke test for vacuum leak???

[towiseman]

Yes. minor leaks. nothing major. According to tse minor leaks are not a problem. vacuum lines are fine.
What else can cause it? Do the freeze frame info I typed mean anything?

[tempfixit]

Originally Posted by towiseman

Yes. minor leaks. nothing major. According to tse minor leaks are not a problem. vacuum lines are fine.
What else can cause it? Do the freeze frame info I typed mean anything?

Where are the leaks??? I would think any leaks would mean unmetered air in the system which leans it out.

[towiseman]

a loose connection before the intake. tightened it and there was no more leaks but still I get the codes every once in a while. What else can do that?

[77poncho]

towiseman... hi.. not sure if it's related or not.. but i had both of those code on my 1999 windstar.. made me crazy... and after much research it ended up being the isolator bolts and the neoprene gaskets under the clamshell... and mine also apeared to be minor vac leaks etc.. and giving lean codes.. but after i replaced all better.. 2 years strong... ;-).. good luck..

[towiseman]

Thanks. Please let me know where are those isolating bolts and seal?
What does those freeze frame data say anyway?? Do they point to anything?

[danielsatur]

Any unmetered air leaks is a problem.
Repeat smoke test and focus on PCV, EGR, and air intake systems.

[towiseman]

Thanks. Those are fine. No more leaks. It is fine for a couple of weeks and suddenly it happens. Always it is when the car is not warmed up completely and not moving. If there was any undetected leak it would happen when the engine is warmed up as well. the car is running perfectly fine when warmed up. What else can do that?

[danielsatur]

Plastic, rubber, and seals will loose there seal when cold.
What gives the feedback signal to the ECU/PCU ?
H20 sensor

Do both a cold + hot smoke test, befor buying a new upstream H20 sensor.

[pepsi1mn]

pvc rubber elbow going to intake degraded from time and oil ,hard to spot soft too the touch ,smoke will not work because sucking air in

[DeltaP]

What does those freeze frame data say anyway?? Do they point to anything?
__________________________________________________ _________________

Lean codes. Fuel trims trying to enrichen . Alot of good advice here... start applying some of the simple,inexpensive stuff first. Last resort... upstream oxygen sensor.

[towiseman]

Originally Posted by pepsi1mn

pvc rubber elbow going to intake degraded from time and oil ,hard to spot soft too the touch ,smoke will not work because sucking air in

Hi
Thanks for reply. It starts well in the morining but until it is completely warmed up if I am stopped at stop sign or trafic light, the engine looks like it wants to go off but it comes back. kind of hesitate but when it warms up the engine is perfectly fine. I changed idle valve once but did not fix it. what can be that?