[LLewis813]

Bought a 2016 M235i Xdrive with 28k miles last November. Drove it stock for a year now have 33k miles. Car had no problems for the year I drove it stock. Did an oil change, changed all the coolant twice (Texas heat) and got new front tires. I need to get new back tires and brake pads all around here soon.

Anyways, back to business. I just installed the VRSF 5" intercooler, charge pipe and hi-flow catted down pipe this week. After numerous months of COVID-19 related delays and back orders, they finally came in.

I installed the down pipe and intercooler at one shop and the charge pipe at another shop due the first being busy / over-quoting for labor on charge pipe. I had the guys at the second shop check the work of the first shop. Overall, everything was good, except they said the down pipe v-band exhaust clamp was installed slightly askew and touching the subframe. They are going to adjust and fix this issue for me tomorrow. Is this something you guys have experienced? Subframe clearance issues on high-flow catted down pipe with VRSF's clamps?

Yesterday, when driving home from work, I had a CEL come on. I knew this was likely due to all the upgrades I just did and not a more serious problem. The light did not come on until about 1.5 days after install. Roughly 15 miles. I am unsure if this is due to the aforementioned down pipe misfitting or due to the second shop's charge pipe install (directional O-ring issue?). Or due to something else, like the O2 sensor in the new cat, etc.. I took it to a Pep Boys this morning before work and they pulled the codes for me (pictures attached). 7 codes in total, but some appear to be duplicates.

Regardless, I have scheduled a follow up with the second shop and told them to look over everything tomorrow when I take it in again. Should be a relatively quick fix, but wanted to get everyone's opinions.

In addition, I will likely have them install a JB4 (EWG version) tomorrow. I have been debating between JB4, BM3 and MHD for a while and I think JB4 might be the way to go. After the JB4 install, I believe any instant CEL codes that get thrown can be hidden / managed better. I think the JB4 should be able to communicate the new upgrades with the ECU better as well.

Thoughts?

Best,
LL

[jb-slow]

Some of those codes are caused by the cat, I figure if the cat is gunna throw the same codes then you might as well just run catless. Anyway, those can be coded out, the maf codes are probably a slight leak somewhere, check all the clamps on the intake first.

[LLewis813]

Originally Posted by jb-slow

Some of those codes are caused by the cat, I figure if the cat is gunna throw the same codes then you might as well just run catless. Anyway, those can be coded out, the maf codes are probably a slight leak somewhere, check all the clamps on the intake first.

Pretty absurd with how accurate this post was.. I took it in for them to re-position the downpipe and look at the CEL issue. The downpipe was re-installed to not contact the subframe so vibration and echo is way down. Downpipe sounds much better and more quiet, as expected. All good there.

After that, they did a smoke test on the intake system. There ended up being leak in the charge pipe install. One of the pipes or clamps was not fully installed. After they fixed that, they smoked it again and found a slight leak in the right intake inlet. They replaced the O-ring there, smoked again and all was good. No leaks - no CEL. Car felt much, much better after they took care of these issues.

However, driving home from work yesterday, another ~15 miles since the work above was completed, another CEL light came on. Car feels fine and is not in limp mode or anything. I figure this is simply the new high-flow cat throwing codes every 15 miles after reset. I will have them look into it again this week when the JB4 is installed. I know the CEL is thrown when running catless downpipes, but I don't understand why a CEL is thrown when using a high-flow cat downpipe.

[Efftooto]

The high flow cat is still letting more "air" through than the OEM catted pipe - hence the code.
Get bm3 or MHD tune and you'll be golden (more power and no codes).

Chris

[bluesy_cube]

First of all, good to see that the boost leak is caught.

The high-flow cat downpipes do not guarantee the emission test pass nor prevent CEL light... They are still not as effective as the OEM cats which is heavily regulated by the worldwide laws.

If you don't have emission test in your area, you might as well go for catless downpipe and install BM3 or MHD to remove the CEL caused by the catalytic converter related codes.