[NthDegree]

I recently had catless downpipes installed on my car and since then the car has been throwing CEL codes P2097, P2098, P0041, P2C7E, P2C6B, P2C31, P2C6A, P2C7F, and P2C32. After doing research I concluded that it was likely either the the O2 sensors were placed in the wrong downpipes or one of them was damaged on install. I took the car back to the shop I had them installed at and they were all placed in the correct spots. However, they said that one wasn't damaged on install and it was likely damaged as a result of the increased exhaust gas flow from the catless downpipes. I've never heard of something like this happening and was wondering if anyone else had.

[Mike@N54Tuning.com]

Originally Posted by NthDegree

I recently had catless downpipes installed on my car and since then the car has been throwing CEL codes P2097, P2098, P0041, P2C7E, P2C6B, P2C31, P2C6A, P2C7F, and P2C32. After doing research I concluded that it was likely either the the O2 sensors were placed in the wrong downpipes or one of them was damaged on install. I took the car back to the shop I had them installed at and they were all placed in the correct spots. However, they said that one wasn't damaged on install and it was likely damaged as a result of the increased exhaust gas flow from the catless downpipes. I've never heard of something like this happening and was wondering if anyone else had.

Thats not true. The shop is just covering themselves. Damaging the o2s during DP install is not uncommon. See it all the time especially when the o2 are seized in and you need to use a lot of force to remove. Catless downpipes due to flow can't damage the o2 sensor. If that was true you would be seeing countless guys getting o2 problems. I had catless downpipes on my 335 for 5 years 100,000+. Put the stock ones back on and the o2 sensors worked perfectly.

Mike

[NthDegree]

Originally Posted by Mike@N54Tuning.com

Thats not true. The shop is just covering themselves. Damaging the o2s during DP install is not uncommon. See it all the time especially when the o2 are seized in and you need to use a lot of force to remove. Catless downpipes due to flow can't damage the o2 sensor. If that was true you would be seeing countless guys getting o2 problems. I had catless downpipes on my 335 for 5 years 100,000+. Put the stock ones back on and the o2 sensors worked perfectly.

Mike

Thank you for the response. I figured it was them covering because no research I did turned up anything like what they were describing but the shop is reputable and well known so I figured they wouldn't do something like that and there was a chance it was true.

[mike@x-ph.com]

Originally Posted by Mike@N54Tuning.com

Thats not true. The shop is just covering themselves. Damaging the o2s during DP install is not uncommon. See it all the time especially when the o2 are seized in and you need to use a lot of force to remove. Catless downpipes due to flow can't damage the o2 sensor. If that was true you would be seeing countless guys getting o2 problems. I had catless downpipes on my 335 for 5 years 100,000+. Put the stock ones back on and the o2 sensors worked perfectly.

Mike

Agree with Mike on this one. Your shop should take responsibility and pay for the O2 sensor that they damaged

[Jklad]

Originally Posted by mike@x-ph.com

Agree with Mike on this one. Your shop should take responsibility and pay for the O2 sensor that they damaged

Or at least man up and say yeah, they were old and got damaged, your probably due for new ones anyways.

[NthDegree]

Thanks guys. Sent them an email as well as left a message detailing what I found and what I would like them to do. Hopefully they step forward and do the right thing and fix it or at least give me some kind of a discount but judging by the tone with which they spoke to me earlier i'm not holding out much hope.

[Stroker1]

Are you running a tune like a jb4, mhd, cobb or other utility which will allow you to auto-suppress codes? Even with new post cat sensors, you will constantly have codes being generated running catless dps. The codes which are reported are odd in that there are both out of range rich and lean codes along with the "mixed or muttled" code.

[NthDegree]

Originally Posted by Stroker1

Are you running a tune like a jb4, mhd, cobb or other utility which will allow you to auto-suppress codes? Even with new post cat sensors, you will constantly have codes being generated running catless dps. The codes which are reported are odd in that there are both out of range rich and lean codes along with the "mixed or muttled" code.

Yeah i'm running a Cobb AP for the tune.

[limitdown]

My Indy must have been daydreaming the entire week that he was dealing with my downpipes and O2 sensors. They're usually great and I've worked with them on 80%+ of my repairs and mods.
One big issue when working on the DPs and sensors is that you have to wait a few hours for the pipes to cool down before any work can be done. So I had to leave the car overnight each time.
Firstly, he swapped the precat sensors (mixed the left and right). Went back in the next day and left the car with him.
After 2 days of driving, I start seeing funky AFR ratios on my MHD gauges. Then precat codes were thrown. Dropped off the car overnight and had him clean the sensors to see if that would help. No luck, 2 days later I'm still getting the same codes.
I probably could have just replaced 1 sensor, but at 70k miles, the 2nd sensor was probably on its last leg.
I'm not sure if the Indy caused the damaged or if the sensor was on its way out. However I'm leaning toward the Indy's fault. I foot the bill that time as new Bosch sensors weren't too expensive, but mainly because my Indy gives me priority service and super VIP discounts.
If you're planning to mod more and keep this car well-past warranty. I highly recommend building a friendly relationship with 1 or maybe 2 good Indys.

[TrollToll]

If you want something done right...

[limitdown]

Originally Posted by Yournamehere90

If you want something done right...

I wish I still lived back in SoCal with my garage and tools...Living in a packed city and being stuck in a multi storey parking garage is painful...

[n54flamer]

I had the same issues, reset the adaptation values, didn't drive the car for a weekend and no problems since then

[Mike@N54Tuning.com]

Any update on the resolution?

Mike

[NthDegree]

Originally Posted by Mike@N54Tuning.com

Any update on the resolution?

Mike

Called them again today and explained the situation again and they're standing by their claim. So i'm taking the car somewhere else to have the issue diagnosed and fixed. In the end to me it's not worth a huge battle with them over a couple hundred dollars.

[Tiago@VRSF]

Originally Posted by NthDegree

Called them again today and explained the situation again and they're standing by their claim. So i'm taking the car somewhere else to have the issue diagnosed and fixed. In the end to me it's not worth a huge battle with them over a couple hundred dollars.

I'd avoid them in the future, they don't seem to be very knowledgeable nor do they seem to offer any respectable customer service.

[BSM n54iS]

Originally Posted by Tiago@VRSF

I'd avoid them in the future, they don't seem to be very knowledgeable nor do they seem to offer any respectable customer service.

+1

I bet they were just careless with the sensors either by removing them or just in a rush to get the dp's in letting the sensors dangle and knocking them around...just covering their ass trying to take advantage of you. I'd laugh in their face if they told me it was due to increased flow....Duh catless flow more than catted, it's an oxygen sensor not a flowmeter. Get it diagnosed properly and present them with the bill, mention you're a member of bimmerpost, writing a reveiw of this shop and tell us who so others can avoid their stupidity

[NthDegree]

Originally Posted by Black n54is

+1

I bet they were just careless with the sensors either by removing them or just in a rush to get the dp's in letting the sensors dangle and knocking them around...just covering their ass trying to take advantage of you. I'd laugh in their face if they told me it was due to increased flow....Duh catless flow more than catted, it's an oxygen sensor not a flowmeter. Get it diagnosed properly and present them with the bill, mention you're a member of bimmerpost, writing a reveiw of this shop and tell us who so others can avoid their stupidity

I plan on presenting them with the bill as a way of giving them one more chance to redeem themselves. As for their name, I don't plan on releasing it until I have the issue solved and determined it was for sure a bad o2 sensor. Either way ill never be taking one of my cars back there or recommending them to anyone.

[Jeff@TopGearSolutions]

Shop is just trying to put the problem on someone else. It's always the install and to be honest it might not even be their fault still.

O2 sensors are fragile and after an install or 2 they usually fail. It's hard for me to put 100% blame on them considering how easy it is for them to fail from uninstall/install.

When I install o2 sensors, I treat them like a piece of glass.

Consider backing off just a little bit on the shop and realize it's par the course on the install sometimes.

[Tiago@VRSF]

Originally Posted by Jeff@TopGearSolutions

When I install o2 sensors, I treat them like a piece of glass.

I do the same and haven't had one fail in over 30-40 installs. If you treat them with care they will not break during install.

[Miller335]

Definitely get a new shop.
They don't even understand how O2 sensors work.

The pre-cat O2 is exposed to the raw exhaust gas flow, the post cat O2 is exposed to the cleaned up exhaust flow. The difference in voltage pre and post cat is how the system knows the exhaust is being scrubbed by the cat.

HTF do they not know this?
Don't let thrm touch your car again.