Check Engine Light and Codes
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
Check Engine Light and Codes
I noticed my check engine light came on so I took her back to the hangar immediately and ran the codes. I had 8 codes, 6 of which had the H for history and were simple/indignificant codes like battery disconnect, etc.
I had 2 codes under the Powertrain computer (P0171 and P0174). This is for Fuel Trim System Lean (Bank 1 and Bank 2). The curious thing is that the code has H and C after it. Does the H and C necessarily mean that it is no longer a relevant code? What does the C indicate? Do these two codes likely account for my Check Engine light being on? I haven't cleared any codes yet. I may take the car to my tuner this week and have him evaluate.
Any comments would be appreciated.
Jax
I had 2 codes under the Powertrain computer (P0171 and P0174). This is for Fuel Trim System Lean (Bank 1 and Bank 2). The curious thing is that the code has H and C after it. Does the H and C necessarily mean that it is no longer a relevant code? What does the C indicate? Do these two codes likely account for my Check Engine light being on? I haven't cleared any codes yet. I may take the car to my tuner this week and have him evaluate.
Any comments would be appreciated.
Jax
Race Director
Joined: Jul 2007
Posts: 18,681
Likes: 47
From: Reno is so close to Hell you can see Sparks , State Of Confusion
St. Jude Donor '12-'13-'14
I noticed my check engine light came on so I took her back to the hangar immediately and ran the codes. I had 8 codes, 6 of which had the H for history and were simple/indignificant codes like battery disconnect, etc.
I had 2 codes under the Powertrain computer (P0171 and P0174). This is for Fuel Trim System Lean (Bank 1 and Bank 2). The curious thing is that the code has H and C after it. Does the H and C necessarily mean that it is no longer a relevant code? What does the C indicate? Do these two codes likely account for my Check Engine light being on? I haven't cleared any codes yet. I may take the car to my tuner this week and have him evaluate.
Any comments would be appreciated.
Jax
I had 2 codes under the Powertrain computer (P0171 and P0174). This is for Fuel Trim System Lean (Bank 1 and Bank 2). The curious thing is that the code has H and C after it. Does the H and C necessarily mean that it is no longer a relevant code? What does the C indicate? Do these two codes likely account for my Check Engine light being on? I haven't cleared any codes yet. I may take the car to my tuner this week and have him evaluate.
Any comments would be appreciated.
Jax
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
I did just have the care tuned about 100 miles ago or so but not sure why the lean condition would show up after 100 miles and not immediately after tuning?
Race Director
Joined: Jul 2007
Posts: 18,681
Likes: 47
From: Reno is so close to Hell you can see Sparks , State Of Confusion
St. Jude Donor '12-'13-'14
Thanks MB. I will get that lean condition looked at. Before I reset codes or reset battery, I want to address the too lean condition not just make the CEL go away.
I did just have the care tuned about 100 miles ago or so but not sure why the lean condition would show up after 100 miles and not immediately after tuning?
I did just have the care tuned about 100 miles ago or so but not sure why the lean condition would show up after 100 miles and not immediately after tuning?
Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
Supporting Vendor
Joined: Jan 2013
Posts: 407
Likes: 11
From: Mooresville North Carolina
Thanks MB. I will get that lean condition looked at. Before I reset codes or reset battery, I want to address the too lean condition not just make the CEL go away.
I did just have the care tuned about 100 miles ago or so but not sure why the lean condition would show up after 100 miles and not immediately after tuning?
I did just have the care tuned about 100 miles ago or so but not sure why the lean condition would show up after 100 miles and not immediately after tuning?
If you recently installed a cold air intake, you may want to clean the MAF as well, sometimes the filters are too heavily oiled and will get onto the MAF elements, skewing the readings.
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Thread Starter
Melting Slicks
Joined: Nov 2011
Posts: 2,789
Likes: 3
From: Jacksonville FL
It can take a while to set the codes, especially if it's right on the threshold of being lean enough to set that code. Is the car modified? I'd take it back to the tuner and have him go back over it.
If you recently installed a cold air intake, you may want to clean the MAF as well, sometimes the filters are too heavily oiled and will get onto the MAF elements, skewing the readings.
If you recently installed a cold air intake, you may want to clean the MAF as well, sometimes the filters are too heavily oiled and will get onto the MAF elements, skewing the readings.
As has been stated an air leak before the MAF is the most likely cause of the two C codes you have. Also as stated an overly oiled CAI may have deposited excess oil on the MAF screen.
Also a possible cause is leaks in the hoses for the PCV system. Over time the PCV hoses crack and otherwise deteriorate from engine heat and oil.
All 3 should be checked carefully.
Also a possible cause is leaks in the hoses for the PCV system. Over time the PCV hoses crack and otherwise deteriorate from engine heat and oil.
All 3 should be checked carefully.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 301
From: Columbia SC
Understand that H (historical) means it has happened in the past. C (current)means it is happening now. If they both show then it did happen and is still happening. If you shut the car down and check codes, some codes will only show H and not C. I am not sure which ones but it is always a good idea if you are having an issue to check the codes while the car is still running.
PS: If anyone can clarify or provide additional info please feel free to chime in, I will certainly not be offended.
PS: If anyone can clarify or provide additional info please feel free to chime in, I will certainly not be offended.
