[boss306]

my stange will idles smooth but at about 1200-1300rpm then randomly go down to 700rpm then go back to what it was it does not seem to mater if the engine is warm or cold or if i drive hard or easy the mass air meter is clean so is the tb and all of the vacume lines are hooked up i also have to go to the smog shop so i want to fix this before i go thanks for the help.

[STINGREY]

pull codes first, but it sounds like a bad coolant temp sensor.

[mustangplace]

Have you changed the IAC

[boss306]

nope can that couse the problem

[RedFOX1]

x2 on coolant temp sensor but it could be either

[boss306]

first of all thanks for the fast replie and i will check out both of those things also does any body in this place live in cali i just had remove my pypes xpip i have the cats for it just not on yet if i put the cats on can i pass the sniffer as long as i fab the pipe for the smog pump the stock pipe kills the power i could not tell if the car was really faster or if it seamed faster just becuse it was louder and if i cant pass with the xpipe will the bbk xpipe pass i know it was 50 state legal but not any more but will it still pass thanks for the help and sorry for the long post