PEP BOYS read the codes for Free, got 2 codes P0172 and p0175. rich bank 1 and bank 2. the guys stated but wasn't sure it was an Oxygen sensor. what do the experts say. how hard to replace?
well if he said they were the 02 sensors i would replace both. if he wasnt sure, i would take it to autozone for another scan to be positive whats wrong before wasting moneywell if he said they were the 02 sensors i would replace both. if he wasnt sure, i would take it to autozone for another scan to be positive whats wrong before wasting money
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Did you clean the Throttle body? That is often the cause of a rough idle.
The Fuel Air o2 sensor on the manifold is often hard to reach, but the downstream o2 sensor after the catalytic converter is easier to get to.
Code P0172 indicates Bank 1 of the engine has a rich fuel mixture. P0175 indicates Bank 2 of the engine has a rich fuel mixture. Engine Bank 1 is the same side of the engine as Engine Cylinder 1. Engine Bank 2 is the opposite side of the engine. A firing order and cylinder location diagram may be needed to see which side of the engine is Bank 1 or Bank 2.
P0172 is triggered by the engine bank 1?"upstream" oxygen sensor and P0175 is triggered by the engine bank 2 "upstream" oxygen sensor. The oxygen sensor alerts your system when the condition is too rich meaning there's too much fuel int the exhaust stream or too little oxygen in the exhaust stream. The symptoms and causes will help you determine the exact issue and how to fix it.
Your bank 1 or bank 2 sensors will be referred to as "sensor 1" or "sensor 2". Sensor 1 refers to "upstream" sensors, or the ones near the engine and before the catalytic converter. Sensor 2 is "downstream" or after the converter.
P0172 LEXUS - System Too Rich Bank 1
Possible causes
Faulty front heated oxygen sensor
Ignition misfiring
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Faulty Mass Air Flow (MAF) sensor https://www.autocodes.com/p0172_lexus.html
oil gauge check oil level replace sender replace oil filter if no better check engine oil pressure with gauge when hot could be worn oil pump or bearings
P0172 - System Too Rich (Bank 1)
The adaptive fuel strategy continuously monitors the fuel delivery hardware. The test fails when the adaptive fuel tables reach a lean calibrated limit. Refer to Section 1 , Powertrain Control Software, Fuel Trim for more information.
Fuel System.
EVAP canister purge valve leak (when canister is full).
Base engine.
Engine oil contamination.
Air Measurement System.
MAF sensor (contaminated, damaged, or corroded connector).
View Freeze Frame Data to determine the operating conditions when the DTC was set. Observe the LONGFT1 and LONGFT2 PID(s). Refer to Section 2 , Adaptive Fuel DTCs Diagnostic Techniques for more information.
Fuel sensors work in the hottest part of the exhaust and are difficult to remove after a period of time. Many mechanics apply a small amount of never seize to the threads to assist in replacement and future removal. However this affects the grounding of the sensor and can cause fault readings. Ask the mechanic if he did that and follow you idea that the sensors may aftermarket and not suitable for yoyr car
Peter. The dealer did diagnose the problem. They said the car needed all 3 oxygen sensors replaced. They were replaced and the car is now returning codes p0172 and p0175 which are the only 2 codes coming up when the check engine light came on. My question is if the dealer sold me the incorrect oxygen sensors could this cause the computer to incorrectly set the p0172 and p0175 rich fuel mixture codes. There are no other codes coming up. My plan at this point is to check and clean the MAF, check my fuel pressure, and also the TPS but I did not want to waste my time if it could possibly be that the new oxygen sensors where the problem. Any help would be appreciated.
You have big problems here, I suggest you go to the provided links and read about these fault codes and then hire a good technician. Ford P0171 P0174 Lean Codes
those codes are for lean engine condition look for vac leaks at the back of engine to the pcv valve could hear hissing noise with engine running also check egr valve to be stuck open also when was last fuel filter changed? hope this helps .
I should replace both 02 sensors? are you sure its not a Mass Air Flow?
what if you already have new O2 sensors & still have code?
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