Last year my 2.6 CD got the same exact codes, turned out i had some corrosion on the face of the sensor in the MAF, even though the tech 2 said the MAF was working ok.
Tech 2 tells you nothing, it simply interfeaces into the vehicle systems to exract data and codes plus can update software. In your case, the tech 2 user was the issue as correct analysis of the live data will show this fault even though no fault code is flagged.
As KCL says it could effect further parts of the exhaust system. Soon after fitting the MAF the emission light came on again and I got the dreaded 420-430 Cat efficiency codes.
There is only one true cure for these codes and that is to re-locate the secondary lambda sensors to behind the main cat. This works every time as Mick Dundee and Bob Dent will verify.
I think it happened because i drove the car for quite a few miles before i changed the MAF, so it has been quite a few worrying weeks thinking I might need to change the Cats.
They will be fine
I have my MOT at the end of this month so will find out then if the Cats are working properly.
You will find that the emissions will be fine (if there not, it will most liekly be down to another un-related issue)
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Topic: 0170/0173 Fuel trim malfunction banks 1&2 (Read 1874 times)