P0171 P0174

[YellowEdge02]

Hey Guys I've been reading up on these codes 171 and 174 and it seems like theres a few deals with this... I'm not sure which one i should start with. I've replaced the PCV hose and elbow... I've also replaced the MAF. During the past year I have changed the EGR valve, DPFE sensor. Its an 02 Ranger with almost 90K, runs fantastic I think! No bucking of the motor, idles fine... I get about 200-300 miles to the tank depending on how I drive... I'm not sure if i should dish out almost 300 bucks for 3 new 02 sensors.... The check engine light is haunting my dreams... I hate unsolved truck mysteries... I've heard about replacing the Plenum gaskets etc... I personally do not want to get into that!

I am using a actron pocketscan plus, 8 ready codes as followed misfire, fuel, comp, catlyst, evap, 02 sensor, 02 htr, egr. What seems kinda crazy is that i've noticed when i've cleared the codes and have turned on the heat, the check engine light comes on.... ??? maybe it coincidence?

 

[kcm1582]

Have you checked your vac lines for leaks? The gaskets could definitely be to blame if it is leaking air. How about your fuel system? From what I have read both can also cause those codes. If that doesn't work then I would go and take it in for service they should be able to tell you what is wrong.

 

[Ranger44]

Carbon can do alot of nasty things. How's the inside of your egr tube? I know you replaced the valve, but did you clean out the tube when you did that?

I can link at least 7 of those to carbon build up.

What brand of gas do you use? Do they have cleaners? or is it cheap discount gas? If what you have is cheap gas, then it wouldn't hurt to run a tank with shell v-power or Chevron Techron cleaner. Example of good gas include Shell and BP stations. They have these cleaners already added to their gas.

 

[YellowEdge02]

Well I cleared the code after a half tank of using 93 octane and the code has not popped up(yet)... At a half tank i'm at 180 miles which is pretty good!! I usually fill up with reg gas. I'm thinking after this tank and if the code has not popped up, I'm going to use the Shell gas...I really hope This will solve whatever issue.

 

[feellnfroggy]

I would alos go the extra step and take apart the entire upper intake, and clean all the elements with little pockets and hole. Especially the IAC, and EGR. dont use brake cleaner or the like on the egr plunger though.

 

[YellowEdge02]

The code has popped up again. I'm going to go ahead and order the new 02 sensors try that, move on from then....

I searched the 02 sensors, they are not that bad to get to, going keep spraying them with penetrating oil to help... I found some motorcraft brand for under 80 bucks each...I've heard to stay away from bosch.

 

[feellnfroggy]

There is a specific socket for the o2's sensors, its basically an impact socket with a cutaway portion this will make your life easier, that and a propane torch.

 

[YellowEdge02]

Wow they are on there! I just wanted to loosen them up for tomorrow... I got the middle one off, but the first and last o2 sensors are really on there!! It is ridiculous on where the lovely engineers had put these sensors... it put me in an extremely bad mood yesterday...

 

[YellowEdge02]

Had a friend replace fuel filter and all three 02 sensor... This morning had Over Drive off flashing on my dash and the motor is kinda dying at some points... this does this while its at idle...

 

[YellowEdge02]

Thanks everyone for their help! I found a leaky rubber 90 degree elbow that was hidden!! I will post pics of this! Note: it was not the PCV elbow that lead to the Airfilter.

 

[Tagg]

Still waiting on Pics !!!!!!!

 

[rainerk]

I kept getting repeated Check Engine lights. Codes were 171, 174 lean banks 1 and 2 and code 300 periodic missing. I replaced the IAF valve and the MAF. Neither helped. Was starting to tear things apart to replace the intake manifold gasket, when I discovered a tear in a rubber elbow that connects the vacuum tube that goes along the left side of the engine (as looked at from the front) and around the back. The elbow that was torn is the one that connects the tube just below the throttle body. There are also two small water hoses that connect to the same area. The clamp on one of these hoses had worn through the vacuum line.
Hopefully this will help someone fix a very elusive problem.

 

[mge_1]

Thanks everyone for their help! I found a leaky rubber 90 degree elbow that was hidden!! I will post pics of this! Note: it was not the PCV elbow that lead to the Airfilter.

You ever get that pic by any chance? I got both codes too.

 

[mge_1]

I kept getting repeated Check Engine lights. Codes were 171, 174 lean banks 1 and 2 and code 300 periodic missing. I replaced the IAF valve and the MAF. Neither helped. Was starting to tear things apart to replace the intake manifold gasket, when I discovered a tear in a rubber elbow that connects the vacuum tube that goes along the left side of the engine (as looked at from the front) and around the back. The elbow that was torn is the one that connects the tube just below the throttle body. There are also two small water hoses that connect to the same area. The clamp on one of these hoses had worn through the vacuum line.
Hopefully this will help someone fix a very elusive problem.

Would these tubes be located similar on a 95 B4000?