My car was producing a sulphur smell and lacking power then the eml came on with the code p0136. The 2nd o2 sensor was replaced and the pcm was updated. A matter of hours after being replaced the eml came back on with the same code. Whilst iv been trying to figure out why the pcm logged another code, a p0130 which i believe relates to the 1st 02 sensor. Is it likley that the pre-cat sensor was becoming lazy effecting the 2nd o2 sensor or is it likley to be somthing else? The car is still over fueling producing the sulphur smell. Just need to be sure as sensors are very expensive and currently have no access to live data diagnostics to test the sensors. Any ideas?
Possible causes and solutions for having code p0136 followed by p0130? on 2007 Ford Focus
by Craigvxr in Tacoma, WA on April 13, 2013
ANSWER by arturo08 on April 13, 2013
review when car last tuned up. it may be due. rec. fuel system clean. ethanol treatment to 1 tank premium fuel. ethanol blend in fuel causes build up in fuel system, combustion chambers, exhaust system and causes increased wear to spark plugs. build up can trip your sensors with false reading.