Issues after JDL catted UEL install
 

Edit... Did not disconnect battery.

(Car info. 2017 BRZ AT. Drop in filter, Q300, intake tube. ) No tune.

Today I had my mechanic install my new JDL catted UEL. Sounded awesome, and everything felt OK. As I was driving home I felt a slight knock when my foot was pressed on the brake pedal. Not to mention it sounded like metal vibrating somewhere in that area. I thought that it was just a normal effect of the new header.

Driving further I noticed the car dropped low in RPM when stopped. It went to 500 RPM and felt as if the car was going to stall. As I pressed on the accelerator the car hesitated and didn't move much. It then accelerated quickly. (This has happened 4-5 times so far) I thought to myself that the ECU might be learning the new equipment, but somehow this doesn't seem normal. I have a o2 spacer, but the CEL came on anyways after about 35 miles.

I only used a new gasket where the header meets the exhaust components. (Excuse my lack of specifics). The original gaskets were used on the other two connection spots. Car has less than 6k miles on it so I figured they shouldn't have been that bad.

Sorry for the lengthy post, but I am just a little concerned with what is going on.

Thanks in advance.

2017 WRB BRZ

Get a tune.

Is this the solution? If so I will buy an OFT. I just don't want "get a tune" thrown out here without any info backing it up.

2017 WRB BRZ

Well you added a new part to your engine that allows more exhaust flow than the ECU can handle and now the car is acting strange.....I'm not going to repeat advice for you that has been posted one million times and then some on this same forum, you're problem isn't unique. This forum has an excellent search feature.

I appreciate you repeating it for the 1,000,001th time. Half sarcasm...
But thanks for the info. I do appreciate it. :)

2017 WRB BRZ

While a tune would be beneficial for sure, I'm not sure that's the only thing going on. I had my JDL catted UEL header on for a month before I got an OFT and didn't have any issues other than the cat efficiency CEL coming on occasionally. No metallic rattling noises either. Check and make sure the header bolts are all still tight. They can come loose after a heat cycle.

I will message my mechanic and bring it in for him to look at. He guarantees his work so I'll have him look at it again.

My question is.. Is it engine knock? I don't know. I'll have to wait and see.

2017 WRB BRZ

It is a 2017 though...

Can you expand on that please?

2017 WRB BRZ

I believe there are some changes to the 2017 refresh that may mean that some exhaust swaps might not swap in perfectly, leading to leaks and such. I know Openflash is working on tunes for the 2017 models, but I'm not sure if they are ready yet; likely a custom tune would be required. I'm not sure what Ecuteck has managed to come up with at this point. Stopgap fixes like the O2 spacers may simply be insufficient to keep the ECU from giving you a CEL.

Beta tunes are available. I actually purchased an OFT earlier this evening. Should be here by Thursday. We'll see what happens. Maybe an ECU reset will help. Worth a shot.

2017 WRB BRZ

The OFT tunes are not optimized for a JDL catted header on an AT. You'll get a tune that's more dialed in for your car by going ECUTek. I recommend Delicious, and speak from personal experience.

So I think the issue was the way the mechanic installed the o2 spacer. He put it on the bung closest to the front of the car. Reason for that was the o2 sensor cable wouldn't reach otherwise. O2 spacer is supposed to be on rear bung, correct? He dismounted the cable and zip tied it to another part. Let's see if that fixes my issue. Hehe. https://uploads.tapatalk-cdn.com/201...b3541b323b.jpg

2017 WRB BRZ

Yes, the spacer should be on the rear (downstream).

The whole purpose of the spacer is to try and trick the ecu, by placing the sensor further out so it gets less exhaust hitting it.

It's also not guaranteed that it will prevent the CEL though.