My check engine light has been coming on...i had it serviced today the code was saying the problem is the mass air flow sensor reading the car is running lean. I do have a Weapon R intake on the car. Anyone have any ideas as to what i should do. Is there a way to raise the mixture. Is there a higher performance mass air flow sensor available? Any feedback would be much appreciated....THanks.........

 

What? You don't tune a car to compensate for a bad sensor...

What are you saying, the CEL was on before you installed the intake?

If the MAF sensor is indeed the problem, you need to replace it, otherwise you are doing damage to your engine by driving with a leaned out mixture.

As far as I know, you can't tune these cars unless you make changes to the programming on the ECU, which none of us have the resources to do.

 

Did the CEL happen after installing the Weapon R intake system? If the answer is yes, then it's your Weapon R intake system. I had the same issue and went as far as replacing the MAF sensor and still had the CEL issue. The Weapon R intake IMO is the culprit, bad design of the intake system. If you closely look at the 3 hoses and where they connect on the OEM intake and compare it the Weapon R intake; you will notice that all 3 hoses connect on the side of Weapon R intake next to the MAF sensor, bypassing it, causing extra air flow to bypass the MAF and not being read. Since it bypasses the MAF, the extra air flow then causes a leaness issue in the unburnt exhaust, causing the CEL. I have since put back my OEM intake and my CEL P0171, running too lean has gone away, no more CEL.

 

of course i would not put on the Weapon R intake with a sensor on....Yes it came on after the Weapon R...about a year later. my mas bolts down to the custom intake pipe...maybe i just need a new one....or i gotta put the old intake back on...would hate to have to do that....i do not think i am doing damage to my engine....if i reset the computer some times it takes over 500 miles for the light to come back on....so i think it might be running right at the boarder line...or maybe the sensor needs to be cleaned...gonna try all before i put that ugly box back in the car.

 

LOL, I did all the things you mentioned and all happened to me. Your probably right that its probably hovering at the upper limits for running lean. I ended up putting my ugly black OEM intake and my CEL has been resolved. Like I mentioned above, there is a design flaw with the Weapon R intake. Two of the inlet holes should be upstream near the filter so it registers thru the MAF sensor. The other hose should be down stream behind the MAF sensor, just like the OEM intake. I believe if the Weapon R was setup like the OEM intake then we wouldnt be having the CEL issue.

 

that 1mz-engine is highly sensitive when it comes to the intake system. i used to have both, long and short ram intake on mine and i had p0171 running lean/rich code. EVERYTHING is reassembled to the way it was. there is another topic where other members here modded the stock airbox to fit an intake filter w/o any codes thrown.
check here
https://www.clublexus.com/forums/es3...e-chips-2.html