Mid Pipe?

[Diabolic1]

Ok, my Si is throwing the Catalyst efficiency below threshold CEL P0420 or somthing like that. I can pull the fuse to the ECM and it will go off for about 3 tanks of gas. Previously I posted about bad gas mileage and think the cat may be the cause. I'm in about 25 tanks of gas now and average 25mpg in town and 29-30 HWY with the A/C on hight and running about 75-80 mph. Who makes the least expensive mid-pipe w/o a converter. How do I trun off the CEL light? Saw some spark plug no-foul adapers somewhere, but arent't there some MIL eliminators as well? Where do I get them?

[jtyler05si]

1. search
2. post in right section
wow

[Blaine]

1. search
2. post in right section
wow

Yeah that
and get a megan test pipe with o2 sensor to replace your cat. I think thats what your talking about

[jtyler05si]

well he already has an o2 sensor....what he was talking about is where you use the spark plug defoulers to trick o2 sensor while "running dirty" with no cat.

[Blaine]

well he already has an o2 sensor....what he was talking about is where you use the spark plug defoulers to trick o2 sensor while "running dirty" with no cat.

Yeah that :flypig:

[Diabolic1]

1. search
2. post in right section
wow

What section would this be best suited to? Engine related? Didn't see an exhaust section.


I did search, but everyone seems to be biased to what they already have. I want a strait, cold, hard numbers answer. Ex: This part from_________will turn off the CEL and this mid pipe from __________will be the cheapest way to eliminate the converter.

Can you fill in the blanks for me sir?

[Diabolic1]

I called Megan and they quoted me $105 for the test pipe. Does it bolt in place of the cat? Will I get some serious droning? They have some sort of spark plug non-foul piece for $20 to turn off the CEL. Is there nothing electronic that will do the sme? If so, who makes it?

[jtyler05si]

engine section.

first of all, do you want to get rid of the CEL and still run clean (cat)
or get rid of CEL running dirty with a test pipe? (no cat)?

[jtyler05si]

megan makes a fairly cheap test pipe....
especially if you find one used

cheaper than that would be a generic ebay test pipe

[Diabolic1]

I want to lose the cat and the light

[jtyler05si]

okay then, your choices are: test pipe or race header. the race header hits two babies in one swing, better header, gets rid of cat.
with both you will want a defouler...search a bit and you will find the exact instructions for this...

personally, i think the midpipe is the most important to replace. it is most constricting, second is cat.

[Diabolic1]

I want to keep the car stock, but the CEL Light is on because of catalyst failure. I'm going to assume the converter is starting to fail. I don't need to pass emissions, but don't want to stare at a CEL light. The test pipe will eliminate the converter right? It should improve mpg as well I would think.

[jtyler05si]

mmm. dont know about mileage, but it will make it MUCH louder. and yes it replaces the cat.

[jtyler05si]

if you want to go the cheapest route, i am sure you could just put the defouler on your broken catalytic converter. that will be the same as a test pipe i guess.

[Diabolic1]

if you want to go the cheapest route, i am sure you could just put the defouler on your broken catalytic converter. that will be the same as a test pipe i guess.

I thought about that too, but if it's clogged evena little then I may be losing MPG and power. Just want to get it out of the way.