I have an 07 bone-stock Fit Sport and really need help with this one. My MIL illuminated and I read the codes P2271 and P2400. I cleared them since the engine ran fine and is not in an open loop condition. I stopped by an independent garage after 3 drive cycles and they came up with the same 2 codes. Only they wanted to replace O2 Sensor 1 AND 2 AND the cat for $1800. They cleared the MIL for me but, as expected, after 3 drive cycles the MIL came back. By then my appointment with the Honda dealer came and they told me the same two codes but they wanted $2400 to replace the sensors and cat. This is my question: the engine is not running in an open loop condition, gas mileage is not suffering, the engine temp is at 179 . . . do I really have to sink $2400 into this or is there something else that could be triggering this code? I commute 8 miles/day and the car only has 67K on it. Here in the mid-west we've had a harsh winter. I have documented only 87 octane gas from reputable dealers and gas additive was used only once 23 fill-ups ago.

 

nothing pulls up in my system for p2400? as far as p2271 I have no idea why they are trying to sell you anything else other than a secondary 02 sensor. According to diagnosis the only thing relating and would need to be replaced is the secondary o2. From my advice just replace the sensor and have codes erased.

 

I did a quick look up on the codes and the P2271 is O2 Sensor Signal Stuck Rich and the P2400 is Evaporative Emission System Leak Detection Pump Control Circuit/Open.

If it were my car and I had no test equipment, I would pull the cat and look at it or try and pull the O2 and get a look into the cat or even put a boroscope into the O2 hole to check the cat element for any melted spots or internal cracks.

If the O2 is good then it could be reading the actual exhaust condition. You would have to monitor the fuel trims with a scanner and either induce a lean condition and watch for a fuel trim change or sniff the tail pipe with a 4 gas analyzer and see if its really running rich.

If the O2 is giving a false reading of rich then it could be a bad sensor.

The 2400 code is an evap code and is entirely something else.

So, could you have a bad or partially clogged cat that would cause the O2 to read rich? Yes, you might and they may be assuming it from typical codes found with a bad cat or they may have done a back pressure test and it failed.

Most of what i described is probably more than you are equipped to do since you brought it to two different shops to read the codes. The equipment needed to scan it, sniff the tail pipe and look into the cat is shop equipment. Some of the guys here may have that stuff for personal use but I can guarantee that most people will never have that stuff at home.

Sounds like you should find a buddy who can help you tear this apart and do a physical inspection to see if the cat looks melted.

Good luck and let us know what you find if you tear it apart.

 

We'll pull the cat Friday as I have a backlog and my personal ride has to wait. As you guessed we don't have the tailpipe analyzer but since the gas mileage has stayed fairly constant over the last 43 fill ups I tend to go with the plugged/melted cat. I took it to the other two shops on the sly cause as the owner I'm supposed to know everything, but this one has me stumped. The codes/sensors say rich but the engine isn't showing the classic signs of rich. More later, thanks.

 

lol The code is a sensor issue. If u had a clogged cat it would most likly throw p0420. If u had a rich condition it would throw a engine running too rich dtc, SMH... Replace the secondary o2. Most likly will need to replace the a/f sensor also.

 

I'm going to replace the secondary O2 sensor Friday, but while I'm messing around there I might as well pull the cat and get a visual.(After all, it's gonna be on the rack anyway!)

 

Thanks, I just about ready to give up! If it's the ECU know anyone who want to buy . . .

 

Pain in the drain! Pulled out both O2 sensors AND the cat. Replaced both sensors with OEM. Cleared the codes, drove three cycles and wham!the MIL is illuminated again! I knew the tip off was when the engine wasn't running rich. I suppose the ECU is next, what else could be throwing these codes?

 

this sounds like hondata could have helped. For the price you paid you could have bought cat delete and hondata and a new sensor and fixed whatever is causing that code. It could be anything at this point without knowing the history of the car.

 

pull spark plugs and check them. if thet look fine, ignore check-engine light, and recheck plugs next oil change