Year of Manufacture *: 2002 Engine Size and Code *: 1.6 G4D ( Optional ) Scanner Used: Solus Pro and Spi ( Optional) Fault Codes: P0133
Hi all, Vehicle came in with MIL on but no other signs or symptoms at all. Code read with Solus Pro and confirmed with SPi, both vehicle specific and EOBD. DTC - P0133 HO2S B1S1 Low Activity. Fuel trims (LTFT at less than 3% and STFT at less than 1%)and all other data looked fine. Scoped HO2S and sure enough it was very slow to switch at idle and at cruise. With rapid opening and closing of the throttle I was able to get the sensor to switch at about 2hz so clearly no problem there. A quick "google" came up with a mention of the exhaust flexi leaking (on a different model)and was diagnosed by a US main dealer. This was dismissed by the poster and by myself as the flexi is post cat. Decided to start with smoke test to inlet which was all ok and then moved on to exhaust. I was very surprised to see a serious leak at the flexi (even though I couldn't hear it). After replacement of the flexi the HO2S was switching at about 1.75hz at cruise speed. Does this mean that HO2S B1S2 has more of an effect on the fueling than I had previously thought or is there some other explanation? Regards to all, Bryan.
Thanks for the link to that Steve as I hadn't read it. I did have an idea that the post cat sensor would have an effect on fuel trims but didn't know that it would actually slow down the switching of the front sensor. I do now though! Regards, Bryan