Engine Light ON - P0140 Error Code

Hi All,

Please help me as I am having no end of issues with my 2005 Jimny.

My engine light illuminated a couple of days ago and yesterday she started misfiring.

I have attached the image from my OBD reader (taken today) as to what the single error code states, which is P0140 - O2 Sensor... This scenario happened to me back in January. In January I dropped it off to a local garage who carried out the following work:
1st visit: Cleaned out the throttle body and replaced the O2 sensor.
2nd visit (as the above did not solve the misfiring): replaced all four spark plugs, coil pack and conjoining cabling.

This did the trick but now I am experiencing the same problem, although not as bad as back in January with the misfiring, do you guys have any ideas? These two trips to the garage cost me £750 in total and I really do not want to be shelling this kind of money out again.

Thank you all so much and I look forward to hearing back from you.

Derk
 

Hi,
I am thinking cable or connector involved with the 02 sensor. I would start with a visual check of connectors and if they don't look perfect maybe replace with alternatives. If you have a DVM check continuity. You need to start at some point and believing the ODB code is a start, but not always the cause.

Misfire or poor idle is sometimes the crank sensors, so keep that on standby. However you don't normally get a code for these, so not following the normal failure mode. Can you clear the code or is it always displayed after a run?
If you can't clear it it suggests it's a permanent failure and possibly easier to locate.

It's also possible the 02 sensor has just stopped working, but it's a swap and see route unless you have specialist equipment to look at the signal from the sensor.