trouble codes with headers
Team Owner
Joined: Jul 2012
Posts: 34,479
Likes: 532
From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
To answer the question, yes it's more or less normal if you didn't do a tune. You need to turn off the downstream 02 s so they're not throwing codes. I'm assuming you no longer have them. Depending upon where your 02s are now, you can also get codes for them not being hot enough. It's difficult to keep enough heat in the headers.
Instructor
Joined: Jun 2009
Posts: 155
Likes: 20
From: Brentwood Tn
codes
PO174 indicates the MAF is under reporting the air flowing through it. Possible reasons are vacuum leak, dirty MAF, dirty fuel filter or weak fuel pump. Stuck injector or weak fuel injector also a possibility. The PO 420 code is Bank 1. It is an O2 related code. Could be an exhaust leak, bad cat, or bad O2. Check for vacuum leaks and exhaust leaks first. Then look at MAF if its really dirty you can clean with MAF cleaner. Suggest you do not use brake cleaner or other solvents.Check injectors with a noid light. or listen to see if all are clicking. They should all sound the same. Once you have verified no leaks then let car run for five minutes or so and check temp of the front O2 sensor. Use a temp gun or probe. Do not use a finger unless you have one to spare. The O2 should be HOT.
Assuming everything checks out you can look for a good tuner to help maximize the gains from the headers and possibly turn off the rear O2 sensors depending on your local emissions situation. I have a drawer full of O2 sensors that were replaced because the mechanic did not look far enough to find the problem. They are seldom the cause of the problem, they just tell you they are not able to work properly. Headers lose heat fast and make it hard for the O2's to get up to their operating temp.
Assuming everything checks out you can look for a good tuner to help maximize the gains from the headers and possibly turn off the rear O2 sensors depending on your local emissions situation. I have a drawer full of O2 sensors that were replaced because the mechanic did not look far enough to find the problem. They are seldom the cause of the problem, they just tell you they are not able to work properly. Headers lose heat fast and make it hard for the O2's to get up to their operating temp.
Last edited by BTTBSS; Jun 14, 2019 at 09:10 PM.
Instructor
Joined: Jun 2009
Posts: 155
Likes: 20
From: Brentwood Tn
codes
PO174 indicates the MAF is under reporting the air flowing through it. Possible reasons are vacuum leak, dirty MAF, dirty fuel filter or weak fuel pump. Stuck injector or weak fuel injector also a possibility. The PO 420 code is Bank 1. It is an O2 related code. Could be an exhaust leak, bad cat, or bad O2. Check for vacuum leaks and exhaust leaks first. Then look at MAF if its really dirty you can clean with MAF cleaner. Suggest you do not use brake cleaner or other solvents.Check injectors with a noid light. or listen to see if all are clicking. They should all sound the same. Once you have verified no leaks then let car run for five minutes or so and check temp of the front O2 sensor. Use a temp gun or probe. Do not us a finger unless you have one to spare. The O2 should be HOT.
Assuming everything checks out you can look for a good tuner to help maximize the gains from the headers and possibly turn off the rear O2 sensors depending on your local emissions situation. I have a drawer full of O2 sensors that were replaced because the mechanic did not look far enough to find the problem. They are seldom the cause of the problem, they just tell you they are not able to work properly. Headers lose heat fast and make it hard for the O2's to get up to their operating temp.
Assuming everything checks out you can look for a good tuner to help maximize the gains from the headers and possibly turn off the rear O2 sensors depending on your local emissions situation. I have a drawer full of O2 sensors that were replaced because the mechanic did not look far enough to find the problem. They are seldom the cause of the problem, they just tell you they are not able to work properly. Headers lose heat fast and make it hard for the O2's to get up to their operating temp.
