HI, I just picked up a 97 cobra with 90K on it. I didn't no it had a CEL because the bulb was blown until I tried to pass E check. I get codes p0171 an 0174. It idles great and runs smooth. I've sprayed around the intake and vacuum lines with TB cleaner an it doesn't change the idle, I changed the fuel filter. The Previous owner said he had a new H pipe put on, it appears to be a stock style one with 4 cats so I don't think thats the problem. The PO also put a c&l air meter on, I've heard of people having problems with the c&l's could this be causing my problem? I didn't get the stock one to try swaping it back. I don't have a tuner or i'd try turning the rear o2 sensors off to see if exhaust is getting through the cats faster than stock an triping the code. any thoughts? THANKS!