clio

My car is stock apart from a high flow cat, cat back exhaust and Odyssey battery

My car is intermittently, but frequently having an issue. It drives great for 95% of the time, then something twigs and it runs like it's on 3 cylinders, sometimes for 10 seconds and sometimes for a few minutes, then reverts back to normal again.

To address this I have replaced:
Spark plus
Coils (Denso)
MAP sensor
Throttle body and TPS
Overhauling IACV
Fuel injectors
Swapped to a high flow cat

But nothing has fixed the issue.

Here is a video

After looking at the video it might sound like the engine is knocking however it's just the camera is near the exhaust.

Any suggestions appreciated.

liybzd

Any CEL? Year and mileage?

clio

No CEL, 2000 model. 118k miles.

Chuck S

Where are you and what fuel are you using. Neither probably has any significance but ...

-- Chuck

clio

I'm in Australia. I always use the highest grade available here (98 octane) and have put through many tanks of fuel with no remedy to the issue.

Could a faulty primary o2 sensor cause significant problems? I wouldn't think so and figured that would throw a cel.

My next port of call is to check the ecu connections. I've never touched the ecu and doubt it's at fault but I've got to cover all bases.

clio

I have a spare engine so can swap out parts easily - which is what I've done as detailed above.

s2000ellier

check the wiring harness both in the engine bay and the connectors at the ecu in the interior.

Chuck S

The fuel grade is fine. What about the source? Always filling at the same station? Fuel contamination is a suspect in cases like this. As is the fuel filter which is on the fuel pump "easily" found inside the fuel tank.

-- Chuck

clio

Thanks Chuck, I fuel up at different spots however I have been through say a dozen tanks with this issue. It ran like a charm last night driving around and then this morning started it with the problem back. Arghhh
I unplugged the ecu and re-connected, also changed the cam sensors on the valve cover with no success.

Bruunz

I have a used primary 02 sensor and a secondary one (which is faulty and caused a cel (voltage low) but engine ran fine) which is in a broken cat. I'm located in Sydney if you want to use for testing.