Let me begin by saying that we all know that Megan messed up with this design of their 4-1 header, and that this story resulted in a very expensive fix. Overall, with the cost of repairs and new parts, these headers cost me well over 400 bucks.

Saturday morning I was finally fed up with the annoying racket of these things, not to mention the clunky rattling of the crap precat built into them. So I decided to go straight back to stock, where my TRD exhaust actually sounded very nice with my K&N intake and didn't sound like a multi-colored CRX farting its way through the neighborhood. I unbolted everything, got them out, and I kid you not this thing sounded like a rainstick when I moved it around. If you don't remember what a rainstick is, think back to your childhood in arts and crafts and it should come back to you.

Back to the story, I go to remove the O2 sensor and find that it's very difficult to budge. I give it a couple shots of WD-40 to penetrate the threads and another twist and it pops right out. Only here's the problem.

THERE WEREN'T ANY THREADS LEFT.

The O2 sensor (which is actually referred to as the A/F sensor at the dealer) was completely destroyed. The threads looked as though they had overheated and welded together, and upon looking inside the Megan header I could see that chunks of the sensor's threads were broken off and stuck in the threads of the header. Needless to say, I was f-ing ____ed off. So I called up the nearest dealer (after trying PepBoys and Kragen) to get a replacement, and sure enough... $200 bucks for a replacement sensor (big surprise there... )

I get the new sensor back home and go to screw it back into the stock header, only to find that now somehow THE STOCK HEADER SENSOR THREADS WERE STRIPPED TOO! Jesus christ...

Now it's Sunday, and I'm ____ed as hell and $200 bucks in the hole already, and now I had to go to a hardware store to spend EVEN MORE MONEY for a tap and tap wrench to rethread the damn thing. Anyways, I managed to rethread the header without having to drill it out and use helicoil inserts (thank GOD) and the new sensor screwed right in there no problem. I finally got the header all bolted in and went to pull out the anti-fouler rig from the s-pipe (which didn't even work in the first place) and when I looked inside of it, why was I not surprised to see that the added heat from the headers had totally warped and blasted the inside of them. If anything the O2 sensor wasn't getting ENOUGH air since the heat melted the damn thing shut.

Long story short, my car is no longer a fart can, there's no trace of a CEL, and it's back to being emissions and street legal.

Cost of Megan Racing Header from CreativeCompacts.com:
$250

Cost of New A/F Ratio Sensor from Toyota Vallejo:
$218

Cost of Tap and Tap Wrench from Orchard Supply:
$35

TOTAL COST FOR THESE F-ERS:
$503!!!!

This may be an isolated experience, but I've definitely learned my lesson. Before I buy ANY aftermarket part again, I'm going to let it sit on the market for quite a while and let it ferment with the consumers. I feel like a total idiot for buying these things as early as I did, and I'm sure some will probably go ahead and call me one just to be dicks. Bah...

 

i feel your pain... unfortunately the excitement of getting something new sometimes overwelms reasoning... i guess you just have to chalk it up to a lesson learned.. trust me.. i have learned MANY a lesson.

now,. i usually wait to see what people say or the problems people encounter.. and .. yes the TRD exhaust has a very nice note..!!

 

Every car I ever had I put a full header back exhaust system on, but the tC will be the only car I could care less to switch out the header, people can say what they want, but there should be no "fixes" no oh it stripped so I bought another one threads. Way to many problems compared to the couple of hp you get out of the things. tC aftermarket headers get a thumbs down from me.

 

Don't blame Jesus! Sounds like you were mis-screwed by Toyota. Maybe a rookie O2 guy at the factory??? So solly!

 

looking at previous thread Casus you will notice more than one person having 02 issues. Yes the engine needs to be cool, and yes you have to soak the 02 sensor before yanking it out, but its to common based on the posts

 

I must have bought good Megan Heads.. almost 2,000 miles on mine, racing them at least 3 times a day.. and still not a single problem *knock on wood*.. That sucks though.. hope it all works out!

 

Yah... I definitely learned my lesson. An expensive one for sure, but at least I came out of this having learned how to tap new threads should I ever need to. I've never ran into that problem before.

"Everything happens for a reason."

Bah...

I honestly have no idea how the threads on the OEM header got messed up, but when I looked in there the first two rings of the threads were just completely hosed. I didn't have any problems when I pulled the sensor out in the first place... bah.

 

You should always use anti-seize compound on the threads of O2 sensors. That would have probably saved you a lot of trouble.

 

WORD...I will be getting a header soon so I went ahead and pulled my O2 sensor from the factory manifold and put anti-seize on it so I know I wont have problems later on. Takes 2 mnutes to do and can literally save you hundreds of dollars down the road.

 

you should have rub the the threads on the stock header and see if the o2 sensor threads are stuck between the header...

i have over 17500miles on my car when i took my o2 sensors off... like i said before, spray wd-40 every 10 min. intill it starts to "turn"... use a wrench and hammer and tap it intill it starts moving...

when you also take off the other o2 sensor on the s-pipe do the same.... the threads are even longer on the s-pipe... so its a bit more difficult.

i dont get how you guys rip your o2 sensor off... dont aggressively turn and pull with your bare hands, like your literally ripping something out...

 

I too have learned many lessons that way. It's expensive but the knowlege lasts a lifetime! I warned a few here about these things but was told I was an idiot. There is NO viable replacement at this time for the factory header. The benifits do not outweigh the problems. Sorry it happened to you, but it was a good lesson.

 

I was actually pretty careful with removing the sensor. I didn't torque on it too hard, and I also used penetrating oil for the threads. I have no idea what happened but it ended in me buying a brand new sensor. grrrrrr...

 

For the O2 sensor (in the future) always use an anti-seize compound and preferably an O2 sensor socket to remove and install it.

As far as the header, I have not heard of one yet (including the DC header that is sold at the dealerships) that is worth the money. I hope someone designs a quality replacement soon.

 

sorry to hear that.

 

2 cents: for a job like this, I wouldn't use WD40...

I recommend real "Anti Seize" formula you can buy at almost any Auto Store.

 

Marshall, I read it as he was using WD40 to use as a penetrating fluid to break the O2 free from the OEM manifold. (before you can do anything with anti-seize.)

In that case, WD40 works okay, but try PB Blaster the stuff does WONDERS! Same thing, in my experience with doing gaskets and seals...instead of using a generic black RTV silicone use this stuff called "The Right Stuff" it works amazing too.

 

what's an anti sieze?

 

Its a type of grease that is used to keep 2 different kinds of metal from forming a chemical bond with each other and fusing.....like what happens to our O2 sensors. It should be used whenever installing spark plugs into an aluminum head or O2 into header/manifold. It keeps the threads from fusing letting you remove the part without damaging anything. Its available at any auto parts store. It smells bad and is hard to clean up, but it works very well for what it is designed for. TIP: Use anti-seize to lube up polyurethane bushings. It lasts a whole hell of a lot longer than regular grease and will keep the from squeaking a lot longer.

 

the pre-cat broke out from inside of my megan header & the unstoppable CEL, other then that I haven't had any problems. I'm waiting for their replacement in June.

 

You learned a vlauable lesson, one which I learned with my last car. If you notice, I have no engine mods done to my car. I usually like to wait atleast 6 months after a new mod comes out to let others deal with all of the kinks in the design. For forced induction, i'm probably going to wait a year to see how all those kits turn out.