Hello fellow Lexus GX470 owners,
I had my dashboard light up with the Check Engine light, VSC Trac, VSC Off and Skid. We pulled the codes and they are: P1441 and P1444. My GX470 is a 2006.
Any insight would be appreciated. We did reset the codes, and the truck seems to drive better than before, more horsepower.
Thanks in advance !
Cheers
Mike Nielsen

 

That's the secondary injection system. Do a search here for that phrase - it's a common problem on older GX's (and Tundras and Sequoias) that have that emissions system.

Chip H.

 

Mine is having this issue. I pull the battery for 3 min to clear the code when they pop.

Most common issue seems to be a leaky gas cap. They came up with a new part / design and there was a TSB posted. New cap is about $40 at the dealer.

 

If it is air injection I'd go with a bypass kit

http://hewitt-tech.com/store/index.p...ct_detail&p=12

otherwise look at what could be involved to fix....

 

My 2008 GX470 (with 185k miles) has this problem. I started the car last weekend and heard this distinctive "shop vacuum" sound within 2-3 seconds. I purchased a scanner and I got the P1441 code. It seems a rather involved process to have that repair done and I can only guess, at a hefty cost. Although I have seen the bypass kit videos, not one explains what happens if you do not do the repair. Obviously, I would assume these parts are required for the vehicle to operate properly and they are not there as just extra parts. Would you know how it affects the vehicle if the repair is deferred and how long it can be pushed for?

My smog test will be due this year in November, as it is required every other year.

Any information will be greatly appreciated.

Best,
Will

 

IIRC, if you do nothing failed parts from the pump could migrate and clog your SAI system which could be even more costly to repair than a pump/valve replacement. Lots of YouTube videos on this. SAI is designed to run for few seconds at start up only, to help warm up the cats. Just get the bypass and be done. This does nothing in regards to how cleanly your car runs so won’t affect emissions testing at all.

 

Yes, what NTH said...

The pump is just to add (inject) more air to the catalytic converters when they are cold so they will heat up faster and start reacting with the exhaust faster. Basically it is a secondary smog system that runs for 10 seconds only when the car is cold (first start of the day) and no other time. With the bypass kit your car exhaust is being more 'dirty' for a few more seconds on the first cold startup of the day. After that, it does not kick on anymore. You will pass smog fine. Your car will be more than warm enough by the time you get to the smog station. I passed smog in CA just fine with the bypass kit.

I was lucky, my exhaust injection valves were stuck in the 'closed' position so I did not have to put the blocker plates in. From what I hear, most of the time they get stuck in the closed position from the air injection pump debris which as I said, is the easier fix. If your valves are stuck in the open position then you are playing Russian roulette every time you cold start the car to potentially clog your SAI system from what I have heard. Since you are saying you are throwing P1441/P1444 codes, it looks like your valves are stuck open. Probably broken pieces of the air injection fan blades holding the valve open. You can get to each valve flange (two bots) from the fender well so it is not hard to get to but it is in an awkward position to get leverage to crack loose the small nuts.

Below are the codes to determine if your valves (there are two) are stuck open or closed:

• P1441/P1444 – Secondary air injection system switching valve number 2 bank 1/bank 2 stuck open
• P2440 Secondary air injection system switching valve stuck open bank 1
• P1442/P1145 Secondary air injection system switching valve number 2 bank 1/ bank 2 stuck closed
• P2441 – Secondary air injection system switching valve stuck closed

 

Thank you very much for the information and for the advise.

Best,
Will

 

Thank you so much for the detailed and great information.

Best,
Will

 

As a final note. If you do decide to go with a bypass kit, I suggest going with a Hewitt or Slyfox kit and not a RuTech kit (this was my research as of four years ago) due to the RuTech not timing the 'start signal' against the actual 'key crank' very well if you don't turn the engine over right away after inserting the key.
The Hewitt kit is expensive but is basically plug and play. The Slyfox kit expects you to be slightly handy with car wiring and does require you to cut/splice into one wire. The advantage is the Slyfox kit is much cheaper.
I went with the Slyfox kit and have never had issues since. All the wiring is wrapped and tucked so you would never see it. I actually forgot it was even in there till I saw this thread.

 

Thanks again!