P0172 code error

[mcdavidhome]

Hello all. I'm trying to figure out what's the deal with this P 0172 code that won't seem to go away on my 02 explorer 4.0. I recently replaced plugs, wires, ignition coil, MAF sensor and air intake. According to the scan tool data from AutoZone it's saying bank 1&2 are too lean but my truck is running and idling just fine though. Not doing too good on gas though. Does anyone have any suggestions on how to troubleshoot this problem? Thanks

 

[imp]

Hello all. I'm trying to figure out what's the deal with this P 0172 code that won't seem to go away on my 02 explorer 4.0. I recently replaced plugs, wires, ignition coil, MAF sensor and air intake. According to the scan tool data from AutoZone it's saying bank 1&2 are too lean but my truck is running and idling just fine though. Not doing too good on gas though. Does anyone have any suggestions on how to troubleshoot this problem? Thanks

@mcdavidhome
Too lean DECREASES fuel consumption, INCREASES fuel economy. So, an imponderable is presented. How do you know it's not "too good on gas"? P0172 code applies only to Bank 1. If the truck runs as well as you indicate, why are you so concerned?
imp

 

[2Trux]

I believe that the "too lean" code means that the computer is maxing out the fuel adjustment but it is still running lean. This is usually caused by unmetered air getting into the manifold. This could be caused by a bad/cracked vacuum hose, leak in intake hose, or bad/dirty MAF. Since you have replaced the MAF (of course this doesn't mean it's still not bad) I would start looking at all the hoses connected to the intake for splits or breaks.

 

[TechGuru]

P0172 is too rich NOT too lean !!! Which would explain why it's not good on gas...

 

[mcdavidhome]

@mcdavidhome
Too lean DECREASES fuel consumption, INCREASES fuel economy. So, an imponderable is presented. How do you know it's not "too good on gas"? P0172 code applies only to Bank 1. If the truck runs as well as you indicate, why are you so concerned?
imp

Well I'm concerned because the check engine light annoys the crap out of me and it's obviously on for a reason. I don't believe in ignoring check engine lights whether the truck is running fine or not..

 

[mcdavidhome]

I believe that the "too lean" code means that the computer is maxing out the fuel adjustment but it is still running lean. This is usually caused by unmetered air getting into the manifold. This could be caused by a bad/cracked vacuum hose, leak in intake hose, or bad/dirty MAF. Since you have replaced the MAF (of course this doesn't mean it's still not bad) I would start looking at all the hoses connected to the intake for splits or breaks.

Thanks for the info. I finally was able to find the problem. It turned out to be a dirty air filter. After I replaced it, the CEL went off in about 30 min and hasn't came back on since. It's amazing how the simplest of things can get you.

 

[imp]

Well I'm concerned because the check engine light annoys the crap out of me and it's obviously on for a reason. I don't believe in ignoring check engine lights whether the truck is running fine or not..

@mcdavidhome
Understood, and agreed. I was trying to lessen a guy's great concern that his vehicle might be in danger of complete, sudden failure. No, a CEL should not normally be simply ignored. Even though I got home OK, mine placed the vehicle in "Forced Engine Idle". Think about that bind! What one does about a troublesome repeating CEL notification is dependent on the code(s), the degree of seriousness of the codes, and the material loss of huge cost to a malicious dealer or repair clinic which may or may not fix it.

For example, if CEL states "EGR blah, blah,...", and no concern is present for somewhat increased emissions, and no need to pass emissions testing is lingering, the toss-up is, pay big bucks to get the frigging light turned off, or ignore it. imp

 

[mcdavidhome]

@mcdavidhome
Understood, and agreed. I was trying to lessen a guy's great concern that his vehicle might be in danger of complete, sudden failure. No, a CEL should not normally be simply ignored. Even though I got home OK, mine placed the vehicle in "Forced Engine Idle". Think about that bind! What one does about a troublesome repeating CEL notification is dependent on the code(s), the degree of seriousness of the codes, and the material loss of huge cost to a malicious dealer or repair clinic which may or may not fix it.

For example, if CEL states "EGR blah, blah,...", and no concern is present for somewhat increased emissions, and no need to pass emissions testing is lingering, the toss-up is, pay big bucks to get the frigging light turned off, or ignore it. imp

I can see your point and I totally agree. I'm just upset with myself because I overlooked the simple things when diagnosing the problem. It turned out to be a very dirty air filter that was causing the CEL to come on..But at the end of the day I guess I have to accept the fact that I'm only human and it happens..

 

[TimsToolBelt]

Hello all. I'm trying to figure out what's the deal with this P 0172 code that won't seem to go away on my 02 explorer 4.0. I recently replaced plugs, wires, ignition coil, MAF sensor and air intake. According to the scan tool data from AutoZone it's saying bank 1&2 are too lean but my truck is running and idling just fine though. Not doing too good on gas though. Does anyone have any suggestions on how to troubleshoot this problem? Thanks

Same issues here. Done plugs and wires. MAF, carbon cleaning. O2 sensors. leaking thermostat. hose check and replace as necessary. STILL throwing code. Due for inspection 60 days ago. HELP.

 

[Drewmcg]

Uhm, change your air filter?

To Imp's point, a qualification: If CEL light is flashing, its an active misfire. If you ignore it very long, you may destroy one or both catalytic converters, which are expensive....