Check engine light comes on at high speeds

[Jeff99GS]

I have a 1999 eclipse N/T I am In the middle of turboing it. When ever I get on the freeway and open it up, the check engine light comes on???? and then later on after driving it slower the Check Engine light goes off??? Do you guys think thats my first o2 sensor?? why would it come on and off. and it has been doin this since last month before i started turboing. has anyone else had this same problem?

 

[talon749]

I did, but im NA; when i installed my header the same thing happened, so I went down to like autozone and had them scan it, sure enought it was the front O2 sensor

 

[Blitzeclips]

Middle of boosting it? You meen the turbo is installed and test drives give you a CEL?

Do you have a FCD, or missing link? You will need one with your car. If it's not the o2 then a CEL could be early signs of feul cut. I have a different feul setup and dont need a missing link, so I'm not %100 sure...

 

[Jeff99GS]

I did, but im NA; when i installed my header the same thing happened, so I went down to like autozone and had them scan it, sure enought it was the front O2 sensor

No I am getting ready to turbo it I should say. I have almost all the parts in now and I want to fix this CEL before I go boosting it. I do have the missing link but nothing is installed yet. I have the vortech 12:1 FMU and a Walbro255L fuel pump. So basically the CEL light will never come on as long as im on the city streets, but as soon as I get on the freeway it comes on???? and then by the time I get off the exit and drive to autozone to have them check it, the CEL light goes off ahhaahahahah like its playing games with me

 

[BigRand]

are the fuel pump and fmu installed on.

 

[Jeff99GS]

are the fuel pump and fmu installed on.

Nope...Literally Nothing is on the car yet, all i did was mount the intercooler. I have been fixing things on it before I put the turbo on it. It is for the most part bone stock.

 

[DSMcrazy3]

Go up to autozone, if you have to..Get on it on the way to make the CEL come on and get the code pulled when you get there.

 

[Jeff99GS]

Go up to autozone, if you have to..Get on it on the way to make the CEL come on and get the code pulled when you get there.

Well I Have a CEL Now all the time....so I went to autozone and the guy said Its the 2nd
o2 sensor and my coil pack is showing a code too. so I guess I should get the MSD coil pack and new o2 sensor...or do I even need the rear 02 sensor? I just passed ohio Emission Check. are those MSD coil packs anygood?

 

[DSMcrazy3]

I've heard there is absolutely no difference felt when swapping, but I'm sure it does something alittle better than OEM. If it's worth the extra money, I don't know. Just be sure you specify your year when purchasing.

As for the rear o2 you do need it, or you will throw a code, but there is a resistor mod you can do to bypass that code. I'll see if I can find it.

 

[Jeff99GS]

Ok... Now It went back off???????? I dont get it. Why would the coil throw a code? the car runs great!! its not missing, I mean either the coil's bad or it isn't... I dont see how it could be bad and the car still runs great.

Oh yeah... How do you get the Pics by your name and stuff, I can't do it. Is it cause im a new member?