Installing a race header on a 4g94.

Discussion in '7G Lancer and older - Performance' started by 03O.Z., Feb 16, 2015.

  1. 03O.Z.

    03O.Z. Member

    Tomorrow I should be receiving my new exhaust manifold and I will be putting it on same day. I already went and got my emissions tested just in case something goes wrong, since this new exhaust eliminates the first cat. I already have a greddy catback on my lancer and i was just wondering if anyone who has already done an after market exhaust manifold had any problems like check engine light or running bad in certain conditions? Any input would be greatly appreciated. I haven't been on this site in about 8 months but I will be on regularly and I will update with pics.
  2. Jogenmaru

    Jogenmaru Well-Known Member

    you will need to buy a cel eliminator. Since you guys have emmissions you will most likely fail once you put the race header on.
  3. 03O.Z.

    03O.Z. Member

    I thought the same thing. But the other day when i went and got my emissions tested I explained i was getting this test done so i didn't have to worry about failing after i replace the manifold with a race header and he told me as long as my check engine light isnt on (they can test to see of it was on and i reset it) ill pass. As long as there are no mechanical problems im all good. They dont actually check for a cat (which i think is stupid) but they do check for a cat and do vacuum test on OBDI
  4. 03O.Z.

    03O.Z. Member

    But regardless i ran into some problems earlier cause the car had sat for 2 year before i got it the underside was so rusted i have to go to my shop tomorrow morning and grind the bolts on the underside of my exhaust. But as soon as its done i will be be back getting my emissions tested and i will post the results.
  5. 03O.Z.

    03O.Z. Member

    Well it took a bit longer than I expected because of countless complications(all of which were from it sitting for 2 years before i got it, everything was so rusted i had to cut it all out), but I finally got my race header installed and I haven't had any problems such as a check engine light or it running bad. This was hands down the most noticeable upgrade I have done, but I'm sure its cause I already had short ram air intake and a catback installed. My throttle response and acceleration have both increased 20-30% and I can still pass emissions!! (Passing emissions is a big thing in nwi) I will be taking out the second cat with a test pipe from road race motorsports (If you have a 4g94 and are looking for performance parts look them up, they are expensive but they are the best/only parts you will find for a 4g94) and I cant wait to see how she performs.

    Attached Files:

    Last edited: Feb 24, 2015
  6. SilentCool

    SilentCool Well-Known Member

    Great job! I definitely agree with you about RRM
  7. Metalsoft

    Metalsoft Member

    If you delete the Cats your CEL will come on.

    I am surprised you did get it after the header install.