just install a 4 2 1 headers on my single 99 ej and now my check engine light came on . i use the code readers to see what the problem it say low volt on o2 censor and too lean and also it said fuel trim malufunction i thing it the air and fuel mixture aint right can somebody help?

 

well if you disconnect your secondary o2 sensor from the loop it wont give ECM proper readings and mess up the mixture and throw a code ... get yourself a o2 simulator for the secondaru o2 sensor

 

if i dicconnect the 02 censor there will be an opening and where can i get that 02 stimulator?

 

the computer doesnt use the secondary o2 to adjust fuel trim. all it does is make sure the cat is doin it job. just a lil fyi