i have a z6 in a 99 civic.. CEL is code 41 (primary o2 sensor) but thats the only code being thrown. The car idles kinda low at around 500rpm and sometimes while driving when i clutch to slow down the car will shut off because the rpm drops so low. Could this be the IACV or fuel pump? just replaced fuel filter and distributor. also noticed today smoke coming from under the intake mani but couldnt determine the exact location. motor temp was still normal tho and oil level is fine. smelt like burning. any info or tips to try would helpp...