Recent content by Julian Stead

At Idle it is showing incomplete combustion, as in not enough fuel..Too much oxygen.. you’re better off looking at fuel trims and taking note the affect raising the RPM has.

A Cat needs to reach operating temperature and lambda to be close to one for it to function efficiently. If the emission test gets a pass I would just forget about it, if it fails then at least he will know what he is up against. Should have done this first to be honest, but it is done now..

You could just take it and get the exhaust gases checked, most garages in the UK have a 5 gas analyser for carrying out MOT’s, I presume Italy is the same.. If it passes, runs without fault and doesn’t have any stored fault codes then just ignore. If it fails then post the results along with...

Carry out a compression test and post results. Also take a picture of the techstream screen showing fuel trims and O2 sensor readings, in graph form preferably for the O2’s..

It will not smell of unburnt petrol if running on LPG. I am not saying low compression is your issue, just that it is a known issue and you could be chasing your tail if you ignore carrying out this test..

If you are running LPG the first thing you need to do is a compression test and go from there.. They typically lose compression over time due to Valve/Valve seat problems...

Hi Paul, why don’t you pull the cam cover off so you can have a good look. snapped camshaft? check exhaust to inlet cam timing marks etc..

Sorry, I should’ve said an inefficient CAT, it doesn’t mean the CAT is at fault but a fuel delivery issue. A sensor, fuel pressure regulator etc..

I am unsure how you can isolate one injector at a time. The only test our diagnostic kit could do was an activation test on a single injector..

A bad catalytic converter can smell like rotten eggs

for the future, you can take the Temps across the CAT, the gases should be hotter exiting the CAT, use the good CAT for reference...

The voltage and the small amount of switching(moving up and down) is good, nothing to worry about, what is good to see is that your B1S2 is now within spec....If that amount of switching brings up a fault code in the US I would be surprised. All looks good at the moment, hope it stays clear.

A vacuum gauge will diagnose restrictions in the exhaust...I use a mityvac, they can even bleed your brakes... www.youtube.com/watch?v=d-jp1IIJVVk

The problem you have with bank 2 is that the voltage is fluctuating, on a traditional O2 sensor upstream of the CAT you would get a Sine Wave pattern bouncing between 0.1v to 0.9v, if the CAT is efficient the downstream sensor will flat line above 0.45v, now the flat line is important, the more...

I would say heat is the biggest cause for clogged CAT’s, they deform.. A low fuel pressure would cause the engine to run hotter and could Damage your AI switches, now I haven’t worked on a vehicle with an Air Pump, the emission laws didn’t require them in the uk. So a lean mixture would cause...