There's discernible soot collecting on the tail pipe of this 2AZ-FE, 2008 Camry LE. I have a Blue Driver OBD Scan Tool I'm using for raw data collection. Live data shows a reasonable short-term trim number (3.x), most of the time, long-term trim is hovering around 8. When I rev up to 2000 rpm for a minute, the short term trim goes down to near zero, but the long term trim rises to roughly 12. (Parenthetically, there's no P0102 code, no DTC at this time). Additionally, my Blue Driver scan tool registers the MAF at a very low 0.3, and the same sixty-second rev up to 2K rpm makes little difference in that grams per second number. As cleaning the MAF (which I did, last week), I've followed standard instructions, using the CRC-specific cleaner for MAF sensors. The wires look clean, at least without the use of a magnifier lens.
Additionally, my Blue Driver scan tool registers the MAF at a very low 0.3, and the same sixty-second rev up to 2K rpm makes little difference in that grams per second number. As cleaning the MAF (which I did, last week), I've followed standard instructions, using the CRC-specific cleaner for MAF sensors. The wires look clean, at least without the use of a magnifier lens.
The only other recent maintenance in this area is that I cleaned the throttle body with some CRC throttle cleaner. (There was plenty to decarbonate). Subsequently, I've checked to see if the hoses and clamps were reinstalled firmly in place, where the K&N cold air intake connects to these hoses. The K&N air filter is relatively new and clean.
Given all of this, I suspect that the MAF may have malfunctioned (although I have not tested it with a multi-meter).
I'm thinking about doing an inexpensive, used OEM swap: There's a salvage yard with a few Generation Six Camry's available. I thought to harvest one and make that switch. If upon installing the salvage unit, the readings go up to 2 gms or so (assuming that the salvage yard pickup is functional, which is always a wild-card variable), then I'll know that the original MAF "died." (I can always multi-meter test both, salvage and original, as well).
So, these are two issues I'm having currently, with my thirteen year old Camry. My tentative assumption is that they are related. Any advice or thoughts, based on your experience and expertise, would be appreciated.
Be Safe. Be Well.
I would buy a brand new OEM MAF sensor.
Update: I bought a used OEM MAF sensor, same part number (off of a 08 Avalon), out of a salvage yard. No problems, whatsoever, with how the used OEM replacement is performing.
Did it fix both your problems, then?
It's too early to tell whether the accumulation of some soot on the tailpipe will be improved by another MAF sensor and a cleaning of both the MAF sensor and throttle body. The consistency of the MAF readings is much improved, however. Twenty dollars well spent.
As for the soot, it's not overwhelming, and might just be the result of an aging engine. I'm keeping a close eye, now, on oil consumption per thousand miles. I'll know more when I take a long trip (1K or more), which I'm planning to do in May.
Thanks for asking.