MajorCommonEngine

Lexus IS: 2AD-FHV Diesel EGR Valve Carbon Fouling and DPF Clogging

2AD-FHV Diesel EGR Valve Carbon Fouling and DPF Clogging is a common engine fault on the Lexus IS on the 2005–2018 cars, and we rate it major. Putting it right costs $600 to $2,800 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 41 documented faults on the Lexus IS.

Vehicle: Lexus IS
Engine: 2AD-FHV
Years: 2005–2018
Fuel: diesel
Gearbox: auto
System: Engine

This page covers the Lexus IS as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Lexus IS faults41 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the EGR valve or Diesel particulate filter yet. We would rather show none than show a picture of a different part.

What goes wrong

The 2.2-litre 2AD-FHV diesel engine fitted to European and some Asia-Pacific IS 300d models recirculates exhaust gases through the EGR system, progressively coating the EGR valve pintle, valve seat, and intake manifold passages with hard carbon deposits. City-driving cycles that prevent the DPF from reaching the 550-600°C exhaust temperatures needed for active regeneration compound the problem as soot accumulates. A heavily fouled EGR valve stuck open dilutes the intake charge causing rough idle and loss of power; a stuck-closed valve raises combustion temperatures and NOx output.

What you would notice

Rough or lumpy idle quality especially on cold start or at full operating temperature
Black smoke under moderate to hard acceleration
Reduced power output at low rpm or activation of limp mode
DPF warning light illuminating or frequent forced regeneration cycles occurring
Increased fuel consumption as the ECU compensates for degraded EGR control

How to check it

Where to look. EGR valve mounted on the intake manifold upper face; DPF in the exhaust system below the vehicle mid-section

Cold-start the engine and observe idle quality — a rough, uneven idle is indicative of EGR or injector issues. Accelerate briskly on the test drive and check the mirrors for black smoke under load. Request an ECU fault code history scan before purchase — P0401, P0402 (EGR flow), and P2002 (DPF efficiency) are diagnostic flags. Ask directly whether the vehicle has been used predominantly on short urban trips, as this is the primary cause of premature DPF saturation.

Parts involved: EGR valve, Diesel particulate filter.

What it costs to put right

$600 to $2,800 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has this vehicle been used primarily for short urban trips or regular motorway driving?”
“Has the EGR valve ever been cleaned or replaced, and is there a service record for this?”
“Has any DPF warning light appeared, or has the vehicle ever gone into limp mode?”

Now check the Lexus IS you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Lexus IS buyer questions

Is 2ad-fhv diesel egr valve carbon fouling and dpf clogging serious on a Lexus IS?

We rate it major and common on the Lexus IS. The 2.2-litre 2AD-FHV diesel engine fitted to European and some Asia-Pacific IS 300d models recirculates exhaust gases through the EGR system, progressively coating the EGR valve pintle, valve seat, and intake manifold passages with hard carbon deposits. City-driving cycles that prevent the DPF from reaching the 550-600°C exhaust temperatures needed for active regeneration compound the problem as soot accumulates. A heavily fouled EGR valve stuck open dilutes the intake charge causing rough idle and loss of power; a stuck-closed valve raises combustion temperatures and NOx output.

How much does it cost to fix on a Lexus IS?

$600 to $2,800 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Lexus IS years are affected?

Our research records this fault on the 2005–2018 Lexus IS. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.