Hondata

EFICU wrote: Thu Mar 03, 2022 4:58 pm I would be interested in seeing the actual calibration you're running because something is either way off in the tune, or there is a mechanical issue. The fuel trims are very erratic, and in very large swings. At idle alone, it's trying to add 47% on the fuel trims and it's still extremely lean. Either way though, something isn't right somewhere.

I don't see anywhere the AFR is holding near 14.1, but the reason the spike you see to 30 AFR is the fuel injectors shutting off for deceleration, that is perfectly normal. When you're decelerating, the injectors shut off and that's why you see the spike in AFR is because there is no fuel being injected into the cylinder.

Either way we would definitely need to try some thing quickly to get the tune inline. Right now things are really off to a point I haven't seen before, so we would need to test a file or two in order to determine a mechanical issue or calibration issue. What I would recommend is sending you a calibration from a tuned K&N intake setup, and have you start it and let it idle for five minutes with no driving. Depending on how that looks, then have you drive it. But for now, a simple file and have you run an idle test is the place to start IMO.

Let me know.

EFICU wrote: Thu Mar 03, 2022 6:04 pm That defouler on the upstream o2 is definitely the problem. That's why I was worried it would be something mechanical. The upstream o2 sensor cannot be spaced out of the stream or else it can't read properly. With it spaced out of the exhaust, it's not able to get a good sniff of the exhaust stream and that's why the AFR is so erratic.

So the previous owner welded a defouler on to the upstream o2 bung? That's so weird, but I wish it was the first time I've heard of that, sadly it's not.

It's a bit of a gray area on driving the car with how it is. While I know that the reading of the o2 sensor isn't right, that it's reading super lean, but that means it's dumping a lot of fuel into the engine to compensate what it thinks it's seeing. I'm trying to think about what I can do to bandaid it for you right now, but there isn't much I can do. For the rear o2, we can turn it off in the tune. But you shouldn't have issue with the rear o2 sensor unless your cat is failing. Does it have the stock cat in it?

What you need to do is find a way to get the primary o2 sensor in the stream as soon as you can. You would either need to drive it to a muffler shop and have them repair it, perhaps weld a new bung in and cap the stock one. Or you can purchase a cheap test pipe like this one https://www.ebay.com/itm/133964209936?c ... RTEALw_wcB and run it in the meantime. Either way, we need to try to get the sensor in the stream as soon as possible so you can drive it with confidence.

Do you have any pictures of the primary sensor. I'm curious to see what they did and what you're working with.

EFICU wrote: Thu Mar 03, 2022 6:51 pm Wow, that is something. It almost looks like the header is entirely custom, that's wild. That is 100% the problem and hopefully the guy didn't beat on it with that setup, definitely don't drive aggressively with that setup. Granted under wide open throttle (WOT) it doesn't use the reading from the o2 sensor, but still. Sheesh, there isn't much I can do.

For a header, I have had good luck with the 1320 Performance header, PLM, Skunk, and K-Tuned. If you're on the hunt for a header now, look around on forums and or Craigslist maybe. Let me know what you find and what you think. But yeah, I mean, honestly at this point replacing that header or manifold that is in there is a must at this point in order to get back on track. But I know money doesn't grow on trees sadly, so we need to find the best solution we can as soon as you can. Either that or try to find someone with stock header and cat.

I'll see if there is anything I can try to do in a tune to help, but I think we're sort of stuck with what we have at this point. If you need to drive it, just keep it light and normal. But I would drive it as little as possible.

The other thing you can do, if money is tight, you can get a bolt on o2 sensor bung from places like AEM. If you can measure the pipe diameter of the collector that is that gray midsection there, you can drill a hole and and use the bolt on o2 sensor bung for now to get us by. They make them in 2", 2.5" and 3". So if you can measure that pipe where those two come into one, this would work. $40 fix would get you by for a while. Check it out here https://www.aemelectronics.com/products ... sor-mounts

https://www.summitracing.com/parts/avm-30-2355-250

no-weld-bung-3-web.jpg

EFICU wrote: Thu Mar 03, 2022 7:31 pm Sounds good. Just keep me in the loop as you're going through the header decision process. Once we get a header in there we can go in and see how it all looks. Hopefully it's all good, then we can get to tuning it so you can have fun with it.

Happy to help. You're welcome.