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Lambda (O2) Sensors

Posted: Wed May 04, 2016 2:26 pm
by DickDastardly
Hi,

a quick tale of woe regarding the rear lambda sensor on my GF's 2002 2.0 SE Auto.

when she got the car the engine warning light (orange) was on - I suspected emissions. bought a OBD II reader (about £12 off ebay) and sure enough P0138 error code (Bank 1 Sensor 2, High Voltage) showed. new rear sensor bought and after many hours of fighting and wrestling to get the old one out, it was removed and a new one fitted (approx £25 off ebay).

engine light came back on after fuse reset (remove ECU fuses from front fuse box for a minute or two, then replace). Finally got the OBD reader on it and it is now showing P0137 code, which seems to translate into possible leak in the flexi section (quite possible after the beasting I gave the old O2 sensor), or blocked CAT. reset the fault code and the car has made it to work with the light still of, but will wait for a few days to see if it comes back on.

if it does, next will be to temporarily bodge the flexi with a load of aluminium foil tape to try to rule out/in the leak theory.

if this is unsuccessful, I am loathe to spend another £120 on a new CAT. does anybody have any fixes for a blocked CAT? is it possible to just flush it out with carb cleaner, brake cleaner, isopropanol, etc?

any thoughts per above appreciated.

Cheers.

Re: Lambda (O2) Sensors

Posted: Wed May 04, 2016 2:31 pm
by Lexo
Cataclean : http://www.autosessive.com/products/957 ... o_s=gplauk

Halfords do it too. Never used it myself but could be worth a shot.

Re: Lambda (O2) Sensors

Posted: Thu May 05, 2016 10:14 am
by DickDastardly
Cheers Lexo - will fall back to that once i have investigated the possibility of a leak on the flexi.

light came back on, so the OBD reset lasted just 3 trips.

Currently finishing off a tank of fuel with injector cleaner in it (usually do it on rough idling cars to see if it helps any - certainly helped with my son's car).

Re: Lambda (O2) Sensors

Posted: Thu May 05, 2016 7:38 pm
by Shel
Same fault codes and sequence I had last year, then the exhaust snapped clean in half at the flexi pipe rear joint when I hit an unsighted pothole the other side of a speed hump.

Have a good look at the whole exhaust system and run the Cataclean through as Lexo says

Re: Lambda (O2) Sensors

Posted: Fri May 06, 2016 8:21 am
by DickDastardly
exhaust section would be around £40 for the whole centre section, or around £25 for a flexi repair section. compared with over £100 for a Cat, I am keeping my fingers crossed it is as simple as an exhaust leak!