Symptoms
A 'vacuum cleaner' whine for about 30 seconds after a cold start that gets rougher as the pump fails. Owners report codes including P2440, P2442, P2445 and P2432, and one reported random limp mode. GXOR says a failed system usually affects only cold-start emissions, not driveability.
The fix, step by step
- Scan the codes first.
- The pump and its air switching valves sit under the intake manifold, so the manifold has to come off to reach them.
- GXOR lists two routes: repair with a Dorman OE-replacement pump, or delete with a Hewitt Technologies bypass kit.
- A delete may fail emissions inspection where you live.
- One ClubLexus owner's bypass worked for about a year before P2445 returned.
- Fit new intake gaskets on reassembly.
- One owner said the pump was covered by a 10-year/150,000-mile extension, which has long expired on most trucks.
Tools & part numbers
- Scan tool
- socket set with extensions
- torque wrench
- intake manifold gaskets
- air pump and switching valves
Where to buy the parts
Air (smog) pump, 2006 GX 470RockAuto ↗Amazon ↗
Air switching (diverter) valve, 2006 GX 470RockAuto ↗Amazon ↗
Intake manifold gasket, 2006 GX 470RockAuto ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Lexus GX 470 parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.