it returned after about 50 miles...
i got a megan header along with the spacer for the O2 sensor...how do i get it back off? can i just put some washers on the O2 to space it farther away from the s-pipe? or find a longer spacer? or what?

 

ok, first, did you put the CEL eliminator on the second O2 sensor? second, have you checked to make sure its a cat or O2 code?

 

yeah its on the second one...and no i havent checked the code...

 

it seems like megan is the hardest header to maintain CEL free. try using the 3 antifouler trick.

 

what do you mean? just got 3 of them and link them together?

 

yes. the normal mod is 2 antifoulers with most headers but with megan i been reading that it takes 3 for it to work. the o2 sticks out further from the spipe not reading less airflow i suppose. try it the foulers are cheap anyway

 

cool i will try that

 

So what is it? You just put washers under the 02 censors and thats it? a few pennies? Im having the same problem and Im new to this.

 

Since I'm new to all this I forgot to ask. Will after market headers over a period of time ruin the catalytic converter? I thin I got the name rite.

 

There is a thread for this!

search for "antifouler"

they are not just washers

go to your local auto parts store and pick up the HELP BRAND sparkplug foulers #42002 i believe and megan needs 3. you also need a 1/2 inch drill bit to drill a hole out of one

i forgot but i think it goes like this

o2 bung ----> modded antifouler ----> un-modded antifouler ---> o2 sensor

 

or, there are companies that sell them especially for types of cars.

 

Not that I've heard of. Cats are ruined by the engine running too rich and exhausting unburned fuel out the combustion chamber and into the cat. The cat will then burn the fuel and melt its internals. This malfunction can happen whether you have aftermarket parts or stay completely stock.

Wouldn't worry about it though. If the engine runs too rich (or too lean, which is actually worse) the ECU will tell you by generating a CEL.

 

aftermarket headers eliminate the cat.... (on the tc)

 

The stock tC has 2 cats, one in the exhaust manifold (pre-cat) and one in the midpipe (main cat). A header deletes only the pre-cat.

 

It's the other way around I believe.

 

click for converter basics

Toyota does this to meet ULEV specs. Our two cats are the three-way type btw.

 

^^ thats what i was thinking, the one on the mid is just a small little cat

 

umm... isnt it just a main cat and then a resonator.... a cat would be identified by two o2 sensors (one before and one after).. this way the ecm can monitor if it is working.... if so... whether the second cat goes bad or not, the ecm would never know.

 

Yes, the stock midpipe consists of the main cat and resonator. The main cat is not monitored with sensors.

Only the pre-cat in the exhaust manifold is monitored. The pre-cat is located much closer to the combustion chamber than the main cat, so it will run hotter and would be first to be exposed to any unburned fuel that enters into the exhaust stream. So this cat is more likely to fail.

I would expect that on any car diagnosed with a failed pre-cat, the Toyota mechanic would also inspect the main cat.

 

I have a megan header too. If you haven't solved your cel problem. go to auto zone get a package of doorman 18mm anti foulers. Drill one out with half inch bit, you will need a drill press or titanium bit if your are going to hand drill. Put the o2 sensor in the drilled one then screw the other not drilled one one and the reinstall. That should take care of your cel.