Codes P2A00 & P1172
10-19-2018
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Codes P2A00 & P1172
2005 civic 1.7 non vtech dx model sedan
First I had code P2A00 bought a oem Denso sensor part number 234-9005 upstream bank 1 sensor 1 sensor
cleared code a day later I had codes P2A00, P1172, and code p0401 cleared them. They stayed off for a day or two.
Now I have codes P2A00 & P1172 as I replaced the upstream o2 sensor with a factory oem sensor and I don’t think that’s the issue. Car seems to run fine and I’m just trying to figure out what to check.
Any help is appreciated. Thanks.
First I had code P2A00 bought a oem Denso sensor part number 234-9005 upstream bank 1 sensor 1 sensor
cleared code a day later I had codes P2A00, P1172, and code p0401 cleared them. They stayed off for a day or two.
Now I have codes P2A00 & P1172 as I replaced the upstream o2 sensor with a factory oem sensor and I don’t think that’s the issue. Car seems to run fine and I’m just trying to figure out what to check.
Any help is appreciated. Thanks.
10-22-2018
#3
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Re: Codes P2A00 & P1172
Some have mentioned that replacing BOTH bank 1 and bank 2 sensors with OEM Honda or Denso brand sensors has eliminated those codes. The P0401 code is for the EGR system (you must have an EGR valve to the left of cylinder head looking at engine from front) which may need to be cleaned of carbon.
These codes were not after a car wash or heavy rain or similar were they? There are TSBs for other Honda models due to moisture in the exhaust system causing the sensors to trip these codes. Solution was to flash the PCM (to delay the sensor readings while the moisture is burned off at startup) and then replace both sensors with Honda ones.
These codes were not after a car wash or heavy rain or similar were they? There are TSBs for other Honda models due to moisture in the exhaust system causing the sensors to trip these codes. Solution was to flash the PCM (to delay the sensor readings while the moisture is burned off at startup) and then replace both sensors with Honda ones.
10-22-2018
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Some have mentioned that replacing BOTH bank 1 and bank 2 sensors with OEM Honda or Denso brand sensors has eliminated those codes. The P0401 code is for the EGR system (you must have an EGR valve to the left of cylinder head looking at engine from front) which may need to be cleaned of carbon.
These codes were not after a car wash or heavy rain or similar were they? There are TSBs for other Honda models due to moisture in the exhaust system causing the sensors to trip these codes. Solution was to flash the PCM (to delay the sensor readings while the moisture is burned off at startup) and then replace both sensors with Honda ones.
These codes were not after a car wash or heavy rain or similar were they? There are TSBs for other Honda models due to moisture in the exhaust system causing the sensors to trip these codes. Solution was to flash the PCM (to delay the sensor readings while the moisture is burned off at startup) and then replace both sensors with Honda ones.
thank you; I’ll try to replace the downstream one and see if the codes will stay cleared. No I can clear the codes they will stay off they do not come on right after start up. It takes it a little bit. Sometimes they will take an hour to come back on. I bought the car for $400 with 200k miles on it with blown head gasket. The car itself is clean and interior is in good shape. It just had a blown head gasket. When I had the intake off I cleaned everything up and got carbon out but didn’t mess with the egr. And just trying to get the codes cleared. I’ll replace the downstream one with a oem one and see what happens.
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