i recently purchased my o2 type s it had some mods already (header full exhaust intake etc.). my CEL was on throwing the p1164 primary sensor malfunction. i got a freeby o2 sensor from local junk yard, it was off an accord. four wire same plug, seemed to be flawless. cleared my codes and my CEL stayed off for a day and now its back throwing p0134 and two p1164 codes. everything i have researched said replace the A/F sensor bank one sensor one. if you do and archive search on here the p1164 code it seems to be specific for accord (not 100% sure tho). my main concern is purchasing a new o2 sensor and it not correcting the CEL based on the mods done to the vehicle. i do have a high flow cat if it makes a difference. the local dealership tells me the only way to resolve the CEL is to go stock..........some1 help me please!!!!!!!!!!!!!!!!!!