Misfire

We fitted a 1.6 VVT to replace 1.3 VVT.

In short we’ve got an intermittent fault where we get a misfire and it runs rough. In between it’s fine.

The code reader says 02 sensor fault. I’ve changed the MAF; no difference. I can’t find the 02 sensor.

Question I’ve got is has anyone any ideas to solve this?

Thank you very much

 

It usually in the exhaust system, in the case of the 1.3VVT I believe its the one in exhaust manifold down pipe toward the rear bulkhead..Not 100% sure as it also has a second device post CAT, but bank 1 is generally pre-cat, bank 2 is post CAT. Someone will be along to confirm which.
Not sure what's happen with them in a 1.6 conversion, assume they are in the same location.
 

A Jimny only has bank 1, bank 2 is if you have a Vee or two exhaust manifolds and two CATs.

Mike is correct Sensor 1 is before the CAT and sensor 2 is after the CAT. Sensor 1 is either in the manifold or in the pipe prior to the CAT.

Either the sensor is faulty or the cabling has a fault. O2 sensors are difficult to remove from the exhaust if they have been in a while, my other car has two CATs and four O2 sensors, I had to remove both CATs to change the sensors and they needed a fair bit of heat to get the old ones out.

When you changed the engine did you change the manifold or did the 1.3VVT fit? If you changed the manifold with the O2 sensor perhaps it is the wrong type for your ECU?

wrote:

The code reader says 02 sensor fault.
 

It would be helpful if you could get the exact fault code - there are several, and they are quite specific, they'll tell you which sensor B1S1 (Bank 1 Sensor 1) or B1S2 (Bank 1 Sensor 2), they'll also tell you what the ECU is detecting as the fault - sensor circuit, sensor response time, etc.

The fault code in the picture is P0134 which is O2 Sensor, Bank 1, Sensor 1.

The top left of the screen says 8/8 so there might be more fault codes that we haven't seen?

The photo also shows O2 Sensor Circuit, No activity Detected, Bank 1, Sensor 1.