First of all, some background on my truck, I have a 2008 Double Cab with the TRD Off Road Package and the 4.0 V6. I have done a couple upgrades, the relevant ones are a TRD Catback (about 2 and a half years ago) and a TRD Cold Air Intake (about 2 years ago).
About 4 months ago my "Check Engine" light turned on, I immediately took it to the dealer so they could run a diagnostic and tell me what was wrong with it. The code came back a problem with the Mass Air Flow Sensor. A new Mass Air Flow Sensor and $300 later I was on my way.
About 2 months later my "Check Engine" light turned on again. Again that same day drove down to the dealer to have it checked out (and enjoy the warranty on their service), the diagnostic code was Mass Air Flow Sensor. Since they couldn't find anything else wrong with it they assumed it was defective, and swapped it out - for free this time.
About a month and a half later, again, my "Check Engine" light turned on, so again, I reluctantly drive down to the same dealer, hopefully it was covered by their service warranty again. Again the diagnostic code came back as Mass Air Flow Sensor, but this time they say when I cleaned my TRD Cold Air Intake filter I must have used too much oil and it had blown on the sensor causing a short. In other words, they swapped out the Mass Air Flow Sensor for a quick $250 and instructed me to go home and reclean out the filter and use less oil this time. So I did.
About 2 weeks later (can you guess what happens next?) my "Check Engine" light turns on... again, and again I drive down to the same dealer - I must be a glutton for misery. The diagnostic - Mass Air Flow Sensor. This time they keep my truck for 2 and a half days, ran every test and monitor they had available. They couldn't find anything wrong with the Mass Air Flow Sensor. They suspected something is wrong with my TRD Cold Air Intake, so for a test, they swapped it out with a stock and found that it "solved" the problem. So what they found was I was triggering a CODE P0101 - "MASS AIRFLOW CIRCUIT RANGE/PERFORMANCE PROBLEM." What they tell me, my TRD Cold Air Intake is messing with the air/fuel ratio. The normal Long Fuel Trim Percentages are 5.5 to 8.5, with my TRD Cold Air Intake I run at 19.5 to 22.5, which is still under the max allowed of 30, but there are instances when it spikes above 30, triggering the Code P101 and my "Check Engine" light.
Their recommendation? Swap out my TRD Cold Air Intake for a stock, or buy a new TRD Cold Air Intake, or run it as is since they cleaned everything out really good and it might have "fixed" it.
I am still not comfortable with what they are telling me. I have had my TRD Cold Air Intake for about 2 years and have never had a problem, so my question is has anybody else ran into similar issues, if so what did you do? Or if you haven't but have some insight on what is really going let me know.