Installed headers and throwing a few codes now

**Sas** · 02-22-2012, 05:34 PM

After a nightmare header install, and lots of custom exhaust work I'm having a few problems. My cars throwing PO171 (bank 1 system to lean) and a PO410 (secondary air injection system)x2 but one is pending. I had the o2 bungs moved to the inside of the LT's rather then facing out, and also had bungs put on after the cats, so I could run all the o2's and stay emissions friendly (and not get the shop in any trouble.) Any idea's of what could cause these codes?

**pajeff02** · 02-22-2012, 06:46 PM

Any chance you have a leak in the exhaust upstream from the driver side header? That could certainly cause a Bank 1 lean code. Do your headers have provisions for the secondary air system, or was it deleted from your car?

**Sas** · 02-23-2012, 05:18 AM

They have the provisions, I have been hearing a slight tick, which I'm guessing is a exhaust leak, but it only shows up under load, not at idle. I've been chasing that one down for almost a week. The engine light wasn't on for the first couple days after the install, it just showed up 2-3 days ago. I did originally have a problem with one of the front side o2's fraying, but I took out the fray, and re-spliced the wires back together, and covered everything in the area with electrical tape. Could that be the root of the problem possibly?

**pajeff02** · 02-23-2012, 06:34 AM

A tick could very easily be an exhaust leak. If the exhaust is sucking outside air above the sensor, that will easily trick the sensor into believing the engine is running lean. As a result, it will call for fuel to be added and your car will end up running too rich. If you have a scanner, you can check your fuel trims to see if this is the case. Members have had mixed results splicing O2 sender harnesses. Best bet with LT's is to install a set of Bosch P/N 13111 senders.

***SMWS6TA*** · 02-23-2012, 08:11 AM

When's the last time you changed the O2 sensors? They need to be changed out about every 70,000 miles.

**Sas** · 02-23-2012, 08:45 AM

I replaced them with the Bosch's when I put the headers in last week. I may have found the problem though, gonna go play with it soon.

**0rion** · 02-23-2012, 09:10 AM

These codes could be related....make sure the hose going to the drivers side manifold isn't leaking and check that gasket on that side where they connect. Since you're hearing an exhaust leak that would be a good place to start.

**Sas** · 02-23-2012, 12:43 PM

Ok I'm stumped... Checked the torque on all the head bolts, and they are all 18-20 lbs, all the hoses are fine and everything's hooked back up properly. The bolts off the AIR are good and tight as well.

**pajeff02** · 02-23-2012, 01:41 PM

Are your spark plugs all snugged down to 11 ft.lbs.?

***SMWS6TA*** · 02-23-2012, 01:58 PM

When they weld up the exhaust were the O2's out of the bungs? I asked because I had one go bad because the welder forgot to take it out when he was doing a new bung and it shorted out the O2. I replaced it and my codes went away.

Also check the plugs & wires for cracks, it happens.

**Sas** · 02-23-2012, 02:07 PM

I'm going to check the plugs torque here in a few, and I'm not sure about the welder, I'll give him a ring while I'm at it. Also, I notice that it smells like I'm running really rich. I think the leak may be around the AIR hose off the drivers side. I did new plugs and wires while I was replacing everything else, so they should still be fine.

**0rion** · 02-23-2012, 03:59 PM

Originally Posted by Sas

I'm going to check the plugs torque here in a few, and I'm not sure about the welder, I'll give him a ring while I'm at it. Also, I notice that it smells like I'm running really rich. I think the leak may be around the AIR hose off the drivers side. I did new plugs and wires while I was replacing everything else, so they should still be fine.

that's why I said I would start there first......that would cause all your symptoms. It would cause a false lean on that side and the pcm would dump fuel over there.

**pajeff02** · 02-23-2012, 05:11 PM

I believe I have several new GM gaskets for the secondary air pipes if you need a set. I tossed my system about 2 years ago and have no need for them.

**00LS12LS6Z28** · 02-23-2012, 05:13 PM

I have the same codes too and I was told it was an exhaust leak. I was told that once I find the leak and get it fixed, I was told to replace my O2 sensors as well, even though I have less than 63K miles

**pajeff02** · 02-23-2012, 05:14 PM

The senders get lazy over time -- as posted, it's not a bad idea to change them in the 50,000 to 75,000 mile range.

**Sas** · 02-24-2012, 04:44 AM

I think I found the problem, looks like one of the bolts off the driver side AIR line is stripped. Tried retapping it, but no good. Gonna look for a nut to fit on the bottom side of the bolt and see if that solves my problem.

**0rion** · 02-24-2012, 11:12 AM

Originally Posted by Sas

I think I found the problem, looks like one of the bolts off the driver side AIR line is stripped. Tried retapping it, but no good. Gonna look for a nut to fit on the bottom side of the bolt and see if that solves my problem.

For some reason I'm pretty sure I did all mine that way when I did my headers. I used block off plates and put sensor safe rtv for the gasket and used bolts with nuts on them.

**Sas** · 02-24-2012, 04:26 PM

Ok, so after putting in the new bolt/nut's as well as a new GM gasket on the drivers side AIR and tightening it down like theres no tomorrow I'm still getting the same codes, and now I can see smoke coming from somewhere off the drivers side header. This is something new, I have the bolts torqued where they are supposed to be and am worried about snapping them off if I go much tighter. Looks like I'll have to get it back on the lift this weekend to just pull the header and double check the big gasket. I've been kicking myself over this project for over a week now, and wish I had never even started the project.

Also asked the guy that welded it all together if he welded with the o2's in, and he says he put them in after everything was done and together.

**0rion** · 02-24-2012, 04:46 PM

did you clear the codes? If you didn't clear them it would take a few drive cycles before they clear on their own. Also, how much have you ran it since the new headers? It'll take some time to burn all the crap off of them when they're new. Make sure there are no wires touching the headers because it will melt them right now. You also could've just got something on them. It really depends on how much and what kinda smoke you're seeing as to what it could be.

**Sas** · 02-24-2012, 05:44 PM

I didn't clear them, I've put about 40 or 50 miles on it since putting it back together. A buddy came by and told me it smelled like the gasket was burning in, so that's a load off my mind as far as the smoke goes. Should I have the codes cleared? I asked the guy not to when I was just in there, didn't want to risk running with a SeS light and not knowing it.