Troubleshooting Header
 

Hey folks. Looking for advice on how to tackle problems related to my new to me PTuning header. Symptoms are high LTFT (10-20) and the right side of the engine bay gets really hot relative to stock. For reference my header is ceramic coated. I am running a standard OFT stage2+(?) v4 tune at the moment. I know I'll need to dial it in, but I want to make sure I have good hardware first.

Question 1: Anyone know a good way to check for double slip joint leaks? Soapy water test of course shows pretty big leak at the slip joints when cold, but I was thinking of ways to test when it's hot (when theoretically sealed) and water just evaporates when the headers are hot. I've also tried holding some paper next to the joints when running but can't really see anything. Maybe see if there's some sort of handheld CO detector?

Question 2: I did also find a leak at the v-band joint using the soapy water test, and was wondering what the order of operations is to try to fix that? My understanding is these don't have gaskets?

Question 3: Is it normal for ceramic coated headers to significantly increase the engine bay temperature on the right side?

Question 4: How delicate/sensitive are the o2 sensor wires? I pinched one on my primary o2 sensor when moving it and that might be contributing to my fuel trim problem.

Your trims may well be high if you are just running an off the shelf OFT tune. My recollection is that the Ptuning header is a EL 4-1 style, and if I am right the OFT tune will be far from optimal. The stage 2 OFT tunes were created around the Open Flash Header they once sold which was UEL in design. EL headers need very different cam timings.

1. I am no help here as I've not had a header with slip joints.

2. You are correct about vbands not using gaskets. You need to make sure the sufaces meet evenly and that the band is tightened correctly.

3. It depends. The stock manifold is insulated well. I wouldn't think it would be way different heat wise. In my experience the ceramic coating does keep things noticeably cooler.

4. Can you see exposed copper? Did it pull where the wires enter the sensor? If no then it is probably fine.

I'm not help on the tune stuff, but let me see if I can help on the rest...

1. Get a smoke stick or incense for when the car is hot and running.

2. V-bands should definitely NOT leak and do not require a gasket. Try loosening both ends, so they can move a little bit, and then tightening the v-band first. If it still leaks after that, it was made wrong.

3. Maybe? More design dependent than anything. Is more of the header tube on the right side?

4. Oddly enough, I've seen where a pinched wire, that look good, caused problems, and another where one had come in contact with a header tube, and still looked good, cause problems.

do a log not to short so we can evaluate better
high ltft is usually a leak near the lambda, if afr doesn t swing suoer much without sense there is no reason to think it s damaged

Yes, it is a 4-1 EL design. I've taken a look at the differences between stage 1 that I ran for years and stage 2+ and there are some overall changes at the high end, but not a lot. It's more like Shiv simplified the maps by eliminating certain correction factors. Not sure how valve timing would make a huge difference in measuring o2 though.

2. Yeah, trying to figure out how to do it properly lol. This is the v-band joint they put right after the collector. Not really sure what the point was of that one lol.

3. Maybe I'm just paranoid lol. I don't remember the engine bay getting hot unevenly before but maybe I just never noticed.

4. I don't think so.

1: Hey that might just work! I assume the method is to light it and hold it near the joints to see if the smoke gets blown somewhere?

2: What do you mean by both ends? I did try loosening the band a bit and retightening while tapping with a hammer.

3. Yes, the exhaust runs along the right side of the engine bay after the merge, that hasn't changed.

4. Any easy way to test it?

1. Correct.

2. loosen slightly at the flanges on both the head and 2-bolt side.

4. Not that I know of, but the FSM probably has a step-by-step.

I don't run anything with v-bands but I've struggled with some pissy ones. They hold ok if the flanges can be aligned before cinching, but they are worthless for drawing up any misalignment.

The secret is to eliminate any cantilevered load before clamping. Then yank the pipe into its hangers afterward. Sometimes even that is impossible. :(

Hmmm... Would the gaskets at the other joints be fine after loosening and retightening? They seemed like single use/deforming gaskets.

I've had mixed results over the years. It's also why I squeeze new ones as little as possible. Leave some cushion for the do-over. It's an imperfect art but there's merit to crushing/torquing "just enough."


It's a learning experience. Maybe have extras on hand but see if you can get away with reusing them.

Bit of a necro but it's my thread and I'll post if I want to... Or something like that. Long post, but I'm still experiencing some issues (end of post) that I could use help on. Thanks in advance!

I wound up unmounting disassembling cleaning up the mating surfaces and reassembling/remounting with the grimmspeed gaskets. Did the v-band last, and that seems to have made the slip fits less leaky. One of the retaining clips was already snapped so I replaced all of those as well.

While disassembled, I measured the slip fits and both sides are all about 0.3mm out of round, wider vertically. Since both inside pipe and outside pipe are the same in that respect, I think it should be alright.

Used smoke sticks and there is still a small leak at the bottom of the slip fits when warm, but it doesn't smell anymore after a long drive so I think they seal better than before under load. Hard to do that on jack stands without triggering my C-O monitor in the garage at least. Also, the ltfts are reasonable for the most part now. I still get some occasional spikes in one cell or another if I'm sitting at a light or in traffic but it corrects itself eventually.

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New issue is that my engine bay gets REALLY hot after the car sits (off) for 10 minutes. Hot enough that I cannot open the hood without gloves. Is that normal for aftermarket headers? They are ceramic coated with Swain Tech which is supposedly good for coatings. Would the leak contribute to this?

Considering using something like this to seal the leak, anyone have any experience with these types of clamps?
https://m.media-amazon.com/images/I/...80_FMwebp_.jpg

Something else I could try is header wrap. Not sure if that's a bad idea on an already coated exhaust. I don't really care what it looks like, but should I be concerned about any sort of interaction between coatings and header wrap?

Any other suggestions? Yes I could get a different header but that feels like giving up lol.

2. I solved V-Clamp joint leakage with red high-temp silicone on the sealing surfaces prior to clamping.

Discovered that the clamps wouldn't work. Because these are double slip fittings, the ID piece actually flares out to fit around the inner slip, so the "smaller" pipe isn't a constant diameter. Also, the clip mount is in the way. I might be able to modify a clamp and use some of that high temperature sealant...

It's baaaaack. Necro #2. Ok I'm done messing with this header. I'm just going to replace it with something else. Options:

A. Get someone to weld the current header closed (I am unskilled in welding). Pro: I don't have to make any purchases traceable to my credit card lol. Con: No idea how it's going to turn out, might still suck, might not be possible.

B. Buy a new cheap header. Pro: not too expensive, likely to bolt up with no issues, I know I'm dealing with a new product, typically lower weight, probably be able to get another of the same model once this one wears out and not mess with the tune the second time. Con: I'll be worried about epa tracking me down, longevity?, longevity with wrap?

C. Buy used expensive header. Pro: best performance and construction, and I do like good engineering. Con: I've been down this road before with used headers and look where it's gotten me. Need to wait for one to be available. New eats up too much budget and I've got other stuff I want to do.

D. Buy another used stock header and gut cat/replace cat with pipe. Pro: cheap, stealth, uses stock heat shielding, will probably outlast the engine. Con: lesser performance, most work, would prefer to weld in a collector/pipe but I have no skills to do so.

E: Just put the stock header back on and be sad about it. Pro: $0, easiest, least naughty. Con: least naughty, least performance

I think I'm leaning towards B or D. Any experience or opinions to help me figure out what to do here? My county does not require smog testing, I intend to leave the stock catted front pipe for now. Might get a higher flow FP in the future. Stock catback for now, but that may also change.