Porsche 911 UK Enthusiasts Online Community Discussion Forum GB

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

Check engine light (again)

WD-40

New member
Joined
31 Jan 2019
Messages
25
A little while ago I had the check engine light come on. My car was already booked in to my local indy for a service, so I asked them to check it out. They found a fault code for an O2 sensor but the tests for this were ok. They noted that the car is running aftermarket cats which is what they concluded to be the fault at the time.

Now, 500 miles later, the light has come on again. It may or may not be the same fault but sounds like in all likelihood it would be - which I guess means it would be another hour or two's labour to make that diagnosis.

Any thoughts on what I can do to avoid having to set up a monthly visit and direct debit to my local (half an hour away) indy, to diagnose / clear the fault? Or avoid replacing the cats - or am I just going to have to bite the bullet...
 
Not sure if it makes any difference, but the cats are X-pipe 200 Cell Sports Cats, from Top Gear - anyone else had similar issues after installing these?
 
2 options:

1) Disconnect your battery for 20 minutes - that clears the fault

2) Buy a cheap code reader that can also clear faults
 
Need a little more info .. pre or post cat lambda sensor ..

What was the fault code ?

Post cat and you are looking for switching on the sensor to indicate a worn or tired cat ..

A flat line either high or low will indicate a rich or a lean mixture .. a crack in the cat close to the exhaust can cause one of these .

If pre cat is it only x1 bank ?

If both then maf .. if a single then again if rich a leaking injector .. if lean then an air leak.
 
I've just ordered a diagnostic code reader which will hopefully tell me what the fault code is and I can go from there.

If it is the O2 sensor then I'm minded to just clear it and motor on...
 
If you are anywhere near Nottingham I'm happy to plug it in to my Durametric.

MC
 
So I received my diagnostic code reader and it bought up the following fault code:

P2098 - Post catalyst fuel trim system too lean bank 2

There was also a 'pending' code of:

P0156 - O2 sensor circuit bank 2 sensor 2

As I said in my original post, my indy previously tested the O2 sensors and they were fine, so I've put my blinkers on and re-set the codes.

Please tell me if I'm being stupid and should get it checked out before something blows up...?
 
Post cat sensor too lean .. you have an exhaust leak young man , its drawing air in and giving the sensor a false reading .

It is possible its something else but ill give you a 90% chance its an exhaust leak .

You can clear the code but it will keep coming back ..

Ive found over the years the best way to prove this fault .. stick a smoke machine up the exhaust .. you will see the smoke come out close to the sensor .. worth getting a garage to have a look but its normally a new cat on that bank to repair .. welding never seems to work .
 
I don't have a smoke machine, so I get a length of tubing, stick one end in my ear, wave the other end around the joints and listen for the leak.

MC
 

Forum statistics

Threads
124,559
Messages
1,441,520
Members
48,974
Latest member
mkrt1972
Back
Top