Top O2 sensor blowout!

[Reedy]

So I had one of those track days yesterday when the car just had gremlins in it.

On an out lap I heard my induction noise suddenly change to a very metallic, raspy sound. You could hear the turbocharger working very clearly and it sounded initially like a bearing had failed. I foolishly ran around for a few laps because the car was still running completely fine.

After I pulled into the pits I popped the bonnet, I thought it was an intake problem but it turned out the top O2 sensor had blown clean out of my DP and was hanging around by the wiring. In this pic you can see the hole where the bung should be and the sensor itself is a bit blurry hanging to the lower left of the hole.



The result of this kinda turned my DP into a screamer pipe - hence the added noise. But this also vented exhaust gases straight into my engine bay and all over the back of my intercooler:

That's one sooty intercooler.

It also partially melted my intercooler shroud, and some other plastic parts around the site of the problem are slightly melted as well. Some of the foil heat shielding is also slightly damaged but it looks like mostly did its part in mitigating any damage.


I took the car to Tunehouse who are patching things back up but they have also told me that not only was the O2 sensor thread stripped and ill need a new one, but the DP also has a crack in it. Exactly where and how bad I do not know, we will sort all of that out next week. I have a CP-e dump pipe FYI.

[RedDjinn]

Strange.... Who installed the DP?

- - - Updated - - -

Strange.... Who installed the DP?

I have a plastic shroud for sale

[Reedy]

iirps installed it of course.

I was going to start asking around for a shroud =P

[chef]

Didn't you get a CEL when it happend?
i like the melted shroud look verry getto

[RedDjinn]

iirps installed it of course.

I was going to start asking around for a shroud =p

lol..

[RedDjinn]

Might also pay to check your cat, make sure its not clogged .

[Reedy]

Didn't you get a CEL when it happend?
i like the melted shroud look verry getto

I did get a cel but it took about 30 minutes of driving before it came on.

http://i.imgur.com/vDL8u3l.jpg

[Jamesa2z]

I did get a cel but it took about 30 minutes of driving before it came on.

http://i.imgur.com/vDL8u3l.jpg

So the CEL did come on after you left? I guess going full throttle around the circuit was enough to not trigger your CEL, which almost makes it a questionable sensor given it wasn't anywhere near the exhaust gases blowing lol.

Did Tunehouse say anything about the CEL codes they disabled possibly being the early detection of a shit install?

[Oldhead]

Looks like your just making to much POWER .
Very unusual for that to happen , possible crack in sensor bung hole ,expanded under heat an opened hole size to blow sensor out .
Hows the thread on the sensor ,not stripped ?????
also possible to crack bung hole by overtightening of sensor,very very weird.
Hope you get going soon,

[Reedy]

The sensor thread is stripped. Need to get a new sensor. Not sure if the threat in the DP is ok, they didn't mention that. Just the sensor and the crack.

[RedDjinn]

You can take the bolt out of you DP just below the sensor and check the sensor thread in the DP. I cant see the thread in the DP being a issue due to it being a harder steel.

[DAN MPS 3]

You can take the bolt out of you DP just below the sensor and check the sensor thread in the DP. I cant see the thread in the DP being a issue due to it being a harder steel.

Softer thread of the sensor hopefully took the brunt of the abuse and left the DP in usable condition.

[Reedy]

Ok the damage report is in.

New top O2 sensor required - thread was stripped (DP thread is ok thankfully).
Dump pipe has cracks where the CAT is welded in - remove and repair required
Some heat shielding in the engine bay has been trashed and needs to be replaced (genuine mazda part required)

Total cost for repairs incl parts and labour is about $1300.

iirps are haunting me......

[Yeldarb]

Ok the damage report is in.

New top O2 sensor required - thread was stripped (DP thread is ok thankfully).
Dump pipe has cracks where the CAT is welded in - remove and repair required
Some heat shielding in the engine bay has been trashed and needs to be replaced (genuine mazda part required)

Total cost for repairs incl parts and labour is about $1300.

iirps are haunting me......

Damn. New DP right there... Factory O2 sensor I'm assuming. Super strange.

Sent from Samsung Note 2 LTE

[Reedy]

Nah don't need a new one, it just needs to be drilled and re welded to stop the cracks.

[Yeldarb]

Do you track and or do the drags a lot? Seems like it must be under more load than the average car.
Cracking DP's doesn't sound fun. Not fun/cheap to swap out either.

EDIT: CP-e DP as well. Thought they were good kit. Although you must have had it installed now for 3 years or so?
Sent from Samsung Note 2 LTE

[Jmac]

whoa..

[SarcasticOne]

Do you track and or do the drags a lot? Seems like it must be under more load than the average car.
Cracking DP's doesn't sound fun. Not fun/cheap to swap out either.

EDIT: CP-e DP as well. Thought they were good kit. Although you must have had it installed now for 3 years or so?
Sent from Samsung Note 2 LTE

@Reedy is resident track god/racecar driver

[Reedy]

Do you track and or do the drags a lot? Seems like it must be under more load than the average car.
Cracking DP's doesn't sound fun. Not fun/cheap to swap out either.

EDIT: CP-e DP as well. Thought they were good kit. Although you must have had it installed now for 3 years or so?
Sent from Samsung Note 2 LTE

I track it all the time.

The theory on the cracked Dump Pipe is that excessive engine movement is fatiguing it. Also explains why the car was popping out of 4th gear approaching turn 4. I have a Stage 2 CP-e RMM tho so either my side mounts also need to be replaced, or the altered geometry of the stage 2 mount actually causes this problem. It's hard to pinpoint but we will be looking further into it.

[Jamesa2z]

Correct me if I'm wrong, but haven't you had the gear pop out at Wakefield (back with the SURE REM) approaching turn 3 going up the hill?