Emissions service question

[XMark]

I had my high flow cats fitted a while ago, done about 1k miles with no issues, last three times I’ve use the car I’ve had the engine light.
Here’s some live data



If I’m reading that right, both downstream sensors are showing voltage below threshold, so do I…..

1. Fit two new O2 sensors?
2. Get it mapped and either delete the code or move the threshold if possible?
3. All of the above?

And no, standard cats won’t be refitted, that’s no fun!

Any insights appreciated

[Go60 Jay]

Hi

What year is your car? It says sensors 1on both banks. If you have 4 sensors, sensor 1 would be on the manifolds, not the secondary high flow cats you had fitted. But I think earlier cars didn’t have the pre cats fitted.

John

[Dungman]

So I don’t have access to the live time data that you have, just a cheap plug in reader.

I fitted 200 cell cats to my 09 4.7 and within a few hundred miles had a multitude of fault codes, coupled with what felt like the occasional misfire and occasional cutting out while slowing for junctions.

Just got the ECU back having sent it to Bamford Rose and all now well again, running great, no codes and improved throttle response.

[XMark]

Go60 Jay said:

Hi

What year is your car? It says sensors 1on both banks. If you have 4 sensors, sensor 1 would be on the manifolds, not the secondary high flow cats you had fitted. But I think earlier cars didn t have the pre cats fitted.

John

Hi John, it’s an “08 4.3 so only one pair of cats, sneakers front and rear on each.

[XMark]

Dungman said:

So I don t have access to the live time data that you have, just a cheap plug in reader.

I fitted 200 cell cats to my 09 4.7 and within a few hundred miles had a multitude of fault codes, coupled with what felt like the occasional misfire and occasional cutting out while slowing for junctions.

Just got the ECU back having sent it to Bamford Rose and all now well again, running great, no codes and improved throttle response.

Good to know they can do it via post, did you have to remove the front wing to get the ecu out or is it doable without? Did you have power mapping done or code and throttle response sorted?

[Dungman]

Easy to get the ECU out with the arch liner removed.

I had it mapped to maximise the benefits of the cats for power, economy and throttle response. Also sent them the air boxes for the additional vent to be fitted. I think they call it a GT conversion or similar.

May do the manifolds at some point in the future.

[XMark]

Dungman said:

Easy to get the ECU out with the arch liner removed.

I had it mapped to maximise the benefits of the cats for power, economy and throttle response. Also sent them the air boxes for the additional vent to be fitted. I think they call it a GT conversion or similar.

May do the manifolds at some point in the future.

Excellent, thank you, I’d also like the manifolds!

[Go60 Jay]

Being a 4.3 with just the 2 cats (I’m jealous) it’ll definitely want mapping to correct the issue. Definitely send it to or visit Bamford Rose. It’ll do the car the world of good. 👍

John