My cel came on, on my ek, and its throwing a code 45. It means system too lean. Last time some one told me that it can be cause from an exhaust leak, which seemed plausible then because my header was cracked but I replaced it, but it still comes on. The weird thing is that I passed smog with it when the code was off. Now it came back again. What can this be? Anyone plz help...

 

Ok so I found the possibilities:

Fuel Pump insufficient flow/pressure
Fuel Feed line clogged leaking
Fuel Pressure Regulator stuck open
Clogged Fuel Pump/Injector
Gasoline doesn't meet Owner's Manual spec
Deteriorated Primary HO2S sensor
Valve Clearance
Exhaust leak

So, damn, where do I get started?

And is there a way to know which one of these it is?

 

anyone?

 

did you reset the computer after you replaced your header?

 

Yep. Every time the code comes on and I reset the ecu, it goes off and then after a while it comes back... What would be the smart thing to start with?

 

whatever the easiest thing to fix is. you didnt start using a cheaper gas did you? Maybe start with the fuel pump. It's pretty easy to change and you can find one on ebay for cheap. There are tons of other people on here that would be way more helpful than me.

 

Cheaper gas, hmm... Well I just put the regular 87 octane that the car requires. I don't know if there is any gas cheaper than that... I might start with the o2 sensor... One question tho, which one is the primary and the secondary?? Is primary the one on the header and secondary the one on the cat??

 

correct about the o2 sensors. when looking for one, try finding a new one instead of a used sensor. It'll cost more, but you'll know it should last a long time. I replaced mine with a used one, and it ended up crapping out a few weeks later.

 

Cool, but if it were the o2's wouldn't that be a different code??

 

I’m not too sure about this, but I think it will only throw the O2 sensor code when it stops working. Don’t hold me to that though. Hopefully the more knowledgeable members will chime in with their .02.