Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that your car's computer is having trouble adjusting the fuel mixture after it passes through the catalytic converter on one side of the engine. It's like trying to balance a see-saw that won't stay level.
The engine control module (ECM) is detecting that the fuel trim adjustments after the catalytic converter are too high on Bank 2, indicating a potential issue with the air/fuel mixture.
P1170 is triggered when the ECM detects that the post-catalyst fuel trim correction value for Bank 2 exceeds the predetermined threshold. This could indicate that the ECM is compensating for a lean or rich condition by adjusting the fuel mixture more than usual.
• Check Engine Light is on
• Poor fuel economy
• Rough idling
• Faulty oxygen sensor
• Exhaust leaks
• Fuel injector problems
ECM: Engine Control Module, the computer that manages engine functions.
Catalytic Converter: A device that reduces harmful emissions from the engine.
• Use an OBD-II scanner to confirm the code.
• Inspect the oxygen sensor and wiring for damage.
• Check for exhaust leaks around the catalytic converter.
• Replace faulty oxygen sensor.
• Repair any exhaust leaks.
• Clean or replace fuel injectors if necessary.
• OBD-II scanner
• Wrench set
• Multimeter
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect and maintain oxygen sensors.
• Ensure fuel system is clean and functioning properly.
• Check for exhaust leaks during routine maintenance.
Engine Performance
• Avoid driving long distances until the issue is fixed.
• Have a professional mechanic inspect the vehicle.
• Monitor fuel economy for any changes.
Check with your vehicle manufacturer for specific warranty coverage on emissions-related components.
This code has been associated with vehicles that have high mileage and may indicate wear and tear on the exhaust and fuel systems.
Moderate – It's important to address this issue to prevent further engine performance problems.
Ignoring emissions-related codes may cause your vehicle to fail emissions testing and could lead to increased pollution.
• Engine at operating temperature
• Vehicle in closed-loop operation
The oxygen sensor is located in the exhaust system, typically after the catalytic converter on the side of the engine known as Bank 2.
Q: Can I drive with a P1170 code?
A: It's possible to drive short distances, but it's best to fix the issue to avoid further damage.
Q: How can I reset the P1170 code?
A: You can reset the code using an OBD-II scanner, but it's important to fix the underlying issue first.
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Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Relevant when the code or supporting diagnostics point toward upstream or downstream oxygen-sensor faults.
This code family often involves upstream or downstream oxygen-sensor diagnosis.
Verify exact sensor position and vehicle fitment before buying.
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Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.