Mazda 6 Forums banner
1 - 14 of 14 Posts

·
Registered
Joined
·
721 Posts
Discussion Starter · #1 ·
I'm pretty sure this is Big Timms custom DP. Does this DP throw a cel since the cat is at the back of the DP instead of right after the turbo? Anyone know the answer?


 

·
Registered
Joined
·
851 Posts
the second o2 sensor is the one that throws the code not this first one
 

·
Registered
Joined
·
820 Posts
im guessing eliminated all together or on that other side of the pipe that we can't see. The second O2 doesn't actually "do" anything in the engine tuning sense. it just measures the air after the cat and compares to see if the cat is up to snuff.
 

·
Registered
Joined
·
851 Posts
which will determine whether a cel is thrown or not.
 

·
Registered
Joined
·
210 Posts
The second one is the one that generally creates the CEL when the down pipe has been modified. If the first one is thowing a CEL you have issues, when the second one throws a cel, you have a light on your dashboard.

If you found this on another board, ask them (the person who owns it) if it throws a CEL
 

·
Registered
Joined
·
3,546 Posts
He posted in the other forum that he does not have a CEL.
 

·
Registered
Joined
·
307 Posts
Almost 2k miles and no codes yet. The high flow cat is about where the stock 2nd cat is. The first O2 is about where it is stock and the snd O2 is behind the cat on the other side of the flange (After the flange to the rest of the exhaust). I think if I were to get any codes, I would have had one by now. Also, $800 built and installed for a 3" SS mandrel bent turbo back exahust is a good price.

Oh yeah, you can dirve the car with no front O2. It goes into speed density mode and drives just like stock......outside of boost of course. I drove it home with no 1st cat because it was siezed in teh pipe and they had to break it to get it out. But the car drove perfectly fine, I could boost, but there was no power in boost. The ECU is a very smart piece of equipment. Now if the O2 was giving incorrect readings, then it would probably have bucked and carried on because the ECU would be trying to tune to the car based on the incorrect readings.
 

·
Registered
Joined
·
851 Posts
all the second o2 sensor does is really just check if the cat is doing it's job
 

·
Registered
Joined
·
1,396 Posts
Almost 2k miles and no codes yet. The high flow cat is about where the stock 2nd cat is. The first O2 is about where it is stock and the snd O2 is behind the cat on the other side of the flange (After the flange to the rest of the exhaust). I think if I were to get any codes, I would have had one by now. Also, $800 built and installed for a 3" SS mandrel bent turbo back exahust is a good price.

Oh yeah, you can dirve the car with no front O2. It goes into speed density mode and drives just like stock......outside of boost of course. I drove it home with no 1st cat because it was siezed in teh pipe and they had to break it to get it out. But the car drove perfectly fine, I could boost, but there was no power in boost. The ECU is a very smart piece of equipment. Now if the O2 was giving incorrect readings, then it would probably have bucked and carried on because the ECU would be trying to tune to the car based on the incorrect readings.
[/b]

Did you just cut and extend the wires on the second O2?
 

·
Registered
Joined
·
998 Posts
Bigg Tim,
I have to say 'Thank you'. This is exactly what I've been looking for in a down pipe. With this setup you can swap out a cat for a test pipe (provided you add another flange).

What's the chances you could get another made and ship it to me? :)

Since CPE doesn't listen, i'll go elsewhere.

Jason
 

·
Registered
Joined
·
721 Posts
Discussion Starter · #12 ·
I guess some of you were confused with the question. I am aware of the function of the second O2 sensor and where it is located. However, because catalytic converters light off quicker the closer they are to the motor the more effective they are at reducing hydrocarbons. the further away it is located the less effective they are. I was wondering if this change in distance was enough to affect the reading of the second O2 sensor and throw an emmissions related CEL. However since Big Timm says no, I think this is the route i will be taking. I can get a custom 3" SS mandrel bent DP fab'd and installed for about $300CDN + cat.
 

·
Registered
Joined
·
307 Posts
Bigg Tim,
I have to say 'Thank you'. This is exactly what I've been looking for in a down pipe. With this setup you can swap out a cat for a test pipe (provided you add another flange).

What's the chances you could get another made and ship it to me? :)

Since CPE doesn't listen, i'll go elsewhere.

Jason
[/b]
I'm going to talk to the guy that made it and see if he wants to make a jig. I don't think mine will bolt up to the stock ssytem since it was all made at once. They extended the 2nd O2, so it is further back in teh exhaust then stock, so that means the DP is longer. I still have the stock setup, so I'll see if he wants to do anything.
 
1 - 14 of 14 Posts
Top