Hey guys whats up? im having some kinda of issue with my 00 si. I just recently changed the headers to some dc sports and since i wanted to run stock piping my mechanic had to create a cat converter for me . Now my issue is when i step on my car around 7k rpms after vtech my car boggles down then picks up boggles down then picks up this is seconds away from each other.One of my friends told me to put a sparkplug non fouler on the cat on the 02 sensor but my mechanic did already .Guys please i have no idea whats going on with my car . Please help me thanks . ill check post in the morning im knocking out now .Laters

 

the o2 in the cat really has nothing to do with fueling of the car (unless i was asleep in that class) it monitors cat effeciency. are you getting a cel? how is the oil level?

 

i havnt checked the oil since i bought the car the elderly man had told me to check the oil because he thought it was kinda low to fill it but i never got around to it and its been like 2 months . I'll check it for sure today . The reason i ask about the cat is because my friend told me it was running rich due to the 02 reading more air or something like that . And this might sound dumb but i have no idea what a cell is . Thanks for your response .Take it easy

 

CEL = Check Engine Light
As for the second O2 sensor...as boostedcivicsir said, that sensor helps to determine catalyst efficiency, which will not make your car run strange...it would just throw a CEL. If this issue started right after the header and new cat were installed I would say there is an issue there, but I couldn't even guess without seeing the work that your mechanic did. Good luck!

 

gotcha on the cel . Well the other night i was on the highway and decided to gun it and as i was catching speed it was doing the bogging down and up thing . I believe it did it like 3 times before i shifted to fourth and boom my check engine light came on . When i got home i turned my car off then on and the cel went away . thats weird huh? . My mechanic unbolted my cat then he cut the bolted ends and welded to small pipes to each them with a flex pipe in the center . Then he adapted a bolt on it so i can connect my o2 sensor . I have no idea what this could be . i'm hooking it up to a computer today after work to see what it tells me . But i'll make sure my engine oil level is good also today .

 

Hmmmm...Are both O2 sensors still attached?

 

yes they are .

 

Just wanted to say thanks to the guys who helped me out . I had no oil in my car it actually took 3 qts yesterday of oil . I have no leaks though so i have no idea what it was about . So again thanks you guy i was really close of blowing my motor . Laters