Test pipe question.

[tollboothwilley]

Just have a question...

The only way to fail emmissions test with test pipes (via OBD II) if its not kicking a CEL is from a visual inspection right?

[TeflonG35]

If the car throws a CEL for anything it will fail inspection.

In MD the use a stick with a mirror on the end to look under the car for cats.

But honestly you can smell when the car doesn't have cats. I seriously considered Gutting the cats like they do on old muscle cars. Just grab a trusty broom and slam the crap out. It wouldn't be real easy cause there is a nice bend in the cats. So I decided not to try. (plus if I messed up I would be screwed cause cats are expensive) I'm just gonna throw the cats back on when I have to get it inspected. Only put on enough bolts to make it stay. Get it inspected and off the cats again.

[tollboothwilley]

don't resonated test pipes give a similar appearance?

I'm just debating between HFC's and test pipes. downside to HFC's is the price.

[toddnos]

Just have a question...

The only way to fail emmissions test with test pipes (via OBD II) if its not kicking a CEL is from a visual inspection right?

in cali you fail via tailpipe emissions from the tailpipe sniffer.

[tollboothwilley]

I think they only use the sniffer test here when the OBD II doesn't connect and work properly.

[Jacko3]

Failure will occur with testpipes anyhow whether by checking the OBD II or through the tail pipes simply because ECU test pipes will move the alpha numbers from a preset range that is okay for passing emissions tests. Emissions tests will catch this deviation from the data even if you don't have a CEL or from the tail pipes. Our Gs actually start failing emmissions well before you ever see a CEL light because it actually goes through a couple of cycles before you actually see that light which is more or less a confirmatory signal rather than an actual signal.

[fbpem1]

i have watched with my own eyes, a car pass with test pipes that had o2 anti foulers or another trick i can't remember what it was. It passed the OBD II compliance test which is when it hooks into the DLC scans for codes if it doesn't see any it passes the car.

Now it WILL fail visual all the time every time

Jacko... As long as the test pipes don't lean the car out to make a lean code or another MIL such as the rear h02s it will pass but won't pass visual

[Jacko3]

I have also heard of some people passing emissions with test pipes---actually met an 04 350z owner who passed emissions with test pipes. That is the point---how do you add test pipes without leaning out the car or without piggy back ECU maps?

I heard that 03 and 04 coupes can pass emissions a lot easier than newer models. So, is this car or G you saw an 03/04? Did it have a piggy back ECU map? Seems like the ECUs are differently coded for each passing year of the same auto model. Mine is an 07 coupe G-35 and I have that trick you talked about---spark plug anti-foulers. so, i wouldn't give many hope that they could pass emmissions with test pipes, while knowing fully well that all our ECUs aren't exactly the same. What do you think?


Modified by Jacko3 at 1:20 AM 11/15/2008