CEL: P2096 and P0456
 

Hey guys, I pulled the codes and its P2096 and P0456. I did a 225 mi drive the other day to Maryland and there were no problems. Later that day when I went to start up the car to get dinner, the CEL came on.. drove back home today (225 mi) and stopped by an autozone to retrieve the codes... seems like the codes are pretty ambiguous as to what they refer.. what do you guys think I should start with? This is a 2004 RX8 M/T with 50k miles.


DTC P2096 - Target A/F feedback system too lean

Possible Cause:

• Leakage exhaust gas
• Rear HO2S malfunction
• IAT sensor malfunction
• ECT sensor malfunction
• AIR system malfunction
• Leakage intake-air
• Front HO2S malfunction
• MAF sensor malfunction
• Fuel line pressure malfunction
• Fuel pump unit malfunction
• Leakage fuel
• Ignition system malfunction
High-tension lead malfunction
Incorrect power supply to ignition coil
Ignition coil malfunction
• Insufficient compression
Metering oil pump malfunction
Engine oil condition malfunction
Rised oil pressure
Oil passage malfunction
Engine malfunction
• Fuel injector malfunction
• PCM malfunction

FIXED
DTC P0456 - EVAP system leak detected (very small leak)

Possible cause:

• Purge solenoid valve malfunction
• Leakage EVAP system
• EVAP system leak detection pump malfunction
• PCM malfunction

The P0456 is most likely your gas cap. Go clean the cap a little bit and then when you put it back on, make sure it clicks 4-5 times.

The other will take some more thought and diagnosis. Need some history on you maintanance........what has been done, at how many miles, and how many miles ago?

Do you have an aftermarket intake......if you do..check the VFAD nipple on the intake..if it isn't plugged you will get the lean code...or other small vac leaks

The evap code is commonly the gas cap...start there :)

^...............The lean code could be MAF, Intake, O2 sensor, etc.
I was going to ask if he had a stock exhaust. Since you asked about the intake, I'll ask about the exhaust. Maybe he's catless and it just showed up???? Been known to happen.


Good thread on P2096 = https://www.rx8club.com/showthread.p...ighlight=P2096

Thanks for the quick reply guys.. Okay no mods except a drop in K&N filter, which i've had since 20k miles.. replaced the rear o2 sensor with a bosch about a year ago to clear a CEL back then for a bad rear o2 sensor. Flooded the engine around 35k miles and had it towed to mazda where they deflooded it and replaced the spark plugs, i believe.

update: When i filled up at some gas station on my way back home from maryland, the clunky fuel pump nozzle leaked a bit on the inside of the fuel door.. so I washed the area out a bit and reseated the nozzle, and the DTC P0456 code is now gone. What's left is the P2096, which actually shows up twice..I borrowed a friend's OBDII scanner, so i'll look at the freeze frame data and see if anything looks off.

Just for fun...check the VFAD vac line ....

well for the sake of closure.. the P2096 DTC went away and the P0456 came back, this time with P0442.. replaced the gas cap with a new one and ran through the drive cycle (more on my troubles with that here: https://www.rx8club.com/series-i-tech-garage-22/iat-sensor-wrong-temp-200345/ ) and no DTCs have since come back after clearing the codes and getting the readiness monitors, including the evap, to set.