OBD2 Codes

[naznomad]

Just got an OBD2 reader. Pulled these codes,but couple of them I cant find the meaning
P0128 (can't find the meaning)
P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0304 Cylinder 4 Misfire Detected (timing off??)
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0452 Evaporative Emission Control System Pressure Sensor Low Input
P1627 (can't find this one)

Are these codes always right or do they show up when there is nothing apparently wrong? Besides the fuel pump issue I am currently having,when the car drives,it drives just fine

[Spider]

Just got an OBD2 reader. Pulled these codes,but couple of them I cant find the meaning
P0128 (can't find the meaning)
P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0304 Cylinder 4 Misfire Detected (timing off??)
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0452 Evaporative Emission Control System Pressure Sensor Low Input
P1627 (can't find this one)

Are these codes always right or do they show up when there is nothing apparently wrong? Besides the fuel pump issue I am currently having,when the car drives,it drives just fine

They are always right but not always the code that is set is caused by an actual engine part.
A lot of times it's just a bad connection at a sensor, the sensor itself is bad or a wire shorted because a mouse ate the isolation off of it.
(see the P.S.)

Look up FAQ and HOW TO stuff in those sections. John T. has a lot of info there.

P0128=STUCK OPEN THERMOSTAT (could be the thermostat or just the sensor: "ECT" sensor)
P0141= (referring to H02S sensor in the exhaust stream past the catalytic converter, might be bad or wiring to it.)
P0304=cylinder 4 misfire..probably that spark-plug wire is shorting out or the plug is bad ? If it's an old code it will clear after 40 successful warm up cycles.
P0420= (more reference to H02S)
P0452=(refers to fuel tank pressure..maybe the gas cap is leaking pressure ?)
P01627=PCM/ECM A/D Conversion Error (Ask a tech about this one) it will clear itself after 40 successful warm up cycles.

Hope this helps

P.S. For rodents that like to hang out in the engine compartment ? I use those sticky traps. No poison. Don't want my lazy cat to eat a poisoned mouse.

[naznomad]

P0128=STUCK OPEN THERMOSTAT (could be the thermostat or just the sensor: "ECT" sensor)
P0141= (referring to H02S sensor in the exhaust stream past the catalytic converter, might be bad or wiring to it.)
P0304=cylinder 4 misfire..probably that spark-plug wire is shorting out or the plug is bad ? If it's an old code it will clear after 40 successful warm up cycles.
P0420= (more reference to H02S)
P0452=(refers to fuel tank pressure..maybe the gas cap is leaking pressure ?)
P01627=PCM/ECM A/D Conversion Error (Ask a tech about this one) it will clear itself after 40 successful warm up cycles.

Hope this helps

P.S. For rodents that like to hang out in the engine compartment ? I use those sticky traps. No poison. Don't want my lazy cat to eat a poisoned mouse.

LOL.We don't have a rodental problem here,its the damn heat that eats through stuff..Anything made out of rubber or plastic under the hood lasts about 5 minutes !
Anyhoo,I didn't clear the codes yet,I'll do that and see if they come back.
The 128 code makes sense though because I knew the thermostat was bad already,but didnt know that was the code for it.
The 452 code is there probably because the fuel pump is out of the tank at the moment.
The 304 code cylinder misfire. Plugs and leads have just been replaced. Could be an old code,I get flashing CEL when i go over 65 for anything longer than a minute or so,so it could be related to that. Again though,the car drives fine and gets 40 mpg,so i'll be buggered if i can see whats wrong with that.