P0437 OBD-II Trouble Code: Catalyst Temperature Sensor Low (Bank 2)

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0437 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0437 code

P0437 is a diagnostic trouble code (DTC) for "Catalyst Temperature Sensor Low (Bank 2)". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0437 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light

Diagnostic Trouble Code (DTC): P0437

P0437 code definition

If the PCM has stored the P0437 code, it means that a three-way catalytic converter is not working as efficiently as it should be according to the manufacturer’s specifications. This code is frequently accompanied by an oxygen sensor code, which should always be diagnosed and repaired first before attempting to diagnose and repair the P0437 code.

What the P0437 code means

The PCM calculates how efficiently each catalyst in each converter is performing, through a variety of sensors, particularly the upstream and downstream oxygen sensors. These sensors’ readings are affected by the fuel conditions and other factors within the engine. The upstream sensor reading is supposed to fluctuate, while the downstream sensor reading is supposed to be fairly steady. If at any time, the readings from the sensors are too similar, or do not fall within the manufacturer’s parameters, the P0437 code will be stored.

What causes the P0437 code?

In many cases, the P0437 code is caused by a faulty catalytic converter. Other causes may include:

  • Faulty catalyst temperature sensor
  • Open or shorted catalyst temperature sensor harness
  • Poor electrical connection within the catalyst temperature sensor circuit

There are several underlying causes to a faulty catalytic converter, such as:

  • Using the incorrect fuel
  • Faulty coolant temperature sensor
  • Faulty fuel injection component
  • Contaminated oil
  • Faulty spark timing
  • Leaking exhaust manifold
  • Leaking down pipe
  • Leaking flex hose
  • Faulty mass air flow sensor
  • Faulty manifold air pressure sensor
  • Faulty pressure regulator

What are the symptoms of the P0437 code?

In many cases, the only symptom that a vehicle owner may observe is the illumination of the Check Engine lamp. If any of the converter components have melted or broken, there may also be a decrease in engine performance, a hissing noise during acceleration, or even an inability to start the vehicle at all.

How does a mechanic diagnose the P0437 code?

The first step in any diagnostic process is to verify the code with an OBD-II scanner. After this process, the mechanic should begin by examining the electrical components for corroded or loose elements, and the exhaust system for leaks. If an issue is present in either area, this issue should be repaired, and the code should be cleared and the system retested.

If, after the mechanic completes these two diagnostic procedures, the code returns, it is most likely that the catalytic converter is bad. The mechanic should continue attempting one repair at a time, clearing the code and retesting as they go, to ensure they pinpoint the problem.

Common mistakes when diagnosing the P0437 code

In most cases, the biggest issue that technicians report is a previous repair that wasn’t in-depth enough. It’s important to find the reason for the faulty catalytic converter, so that the issue does not occur again after a new converter is installed.

The next most common issue is a mistakenly blamed oxygen sensor. Because an oxygen sensor code can be present at the same time as the P0437 code, mechanics may replace this part right away; but the oxygen sensor should be tested for proper operation before it is replaced, because it is usually not to blame.

How serious is the P0437 code?

If the P0437 code is being detected, the vehicle will most likely still be drivable. Unless there are serious breakages within the converter components, this is considered a mild issue. It may affect the vehicle’s ability to pass an emissions test, and it should be repaired when time allows; but it is not an emergency repair that must be performed ASAP.

What repairs can fix the P0437 code?

In most cases, repairing the faulty catalytic converter, and repairing the underlying issue that caused the fault, will fix the P0437 code. Other repairs may include:

  • Replacing a faulty catalyst temperature sensor
  • Repairing an open or shorted catalyst temperature sensor harness
  • Repairing a poor electrical connection within the catalyst temperature sensor circuit

Need help with a P0437 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

trouble codes
Check Engine Light
P0437

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0437 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,636

Rating Summary
3,315
161
42
24
94
3,315
161
42
24
94

AARON

2018 years of experience
11 reviews
AARON
2018 years of experience
First time meeting Aaron and he was awesome! Showed up early and ready to go! Diagnosed my check engine light quickly and easily. Thanks Aaron! Will definitely use Aaron again for future car issues.
1997 HONDA ACCORD - CHECK ENGINE LIGHT IS ON - SACRAMENTO, CALIFORNIA

Robert

17 years of experience
436 reviews
Robert
17 years of experience
Excellent communication and willingness to go the extra mile
2000 SUBARU IMPREZA - CHECK ENGINE LIGHT IS ON - DENVER, COLORADO

Milton

34 years of experience
154 reviews
Milton
34 years of experience
Good
2009 KIA RIO - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Emmette

33 years of experience
269 reviews
Emmette
33 years of experience
Answered all my questions . Very Pleasant to talked to . Completely satisfied .
2006 NISSAN 350Z - CHECK ENGINE LIGHT IS ON - WOODBRIDGE, VIRGINIA

More related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...

Related questions

Q: Car stopped after rough idle

This is a common symptom of a faulty idle air control module. This module regulates the control of air being mixed with fuel at idle. When this is faulty, it will cause an imbalanced amount of air and fuel to...

Q: If i replace my thermostat and my car is still running hot , what else can it be ?

When dealing with issues like these, always start with the simplest options first. The thermostat is only designed to read liquid. If the coolant is low, the reading on your dashboard may not be accurate. The vehicle may have been...

Q: Car isn't shifting when pedal is all the way down and is slow.

Your engine management system is going into "limp mode" when the Check Engine light is illuminated, reducing engine power, and quite likely, leaving your automatic transmission in 2nd gear. This is why you are experiencing greatly diminished performance. Turning your...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com