When is the p0421 code set on a car?
The P0421 code is set when the Engine Control Module (ECM) detects rear HO2S value difference becomes closer to value of front HO2S. The ECM monitors when vehicle speed is 25-60 MPH, load is 22-45 percent and engine speed is 1000-3000 RPM.
What does it mean if your check engine light says po420?
It is important to remember that if your “Check Engine Light” illuminates and someone just simply reads a code of PO420, 421, 430 or 431 this does not necessarily mean the Catalytic Converter is bad! All that code says is either Converter operating below efficency or Converter operating below threshold.
What to do if your OBD scanner says P0420?
Replacing your catalytic converter can ensure efficient operation of your car’s exhaust system. You may also have to replace the oxygen sensor. After you’ve replaced or repaired these two components, check your OBD-II scanner again to ensure you’ve completely solved the OBD-II scanner error code P0420 or P0421 problem.
How to tell if your car has a problem code po431?
1 Bad or Lazy (80,000 + Miles) Upstream O2 Sensor 2 Leaking Injectors 3 Bad Temperature Sensors 4 Bad Mass Air Flow Sensor 5 Miss Fire (Coil Packs) 6 Bad or Old Spark Plugs 7 Clogged Air Filter
What to do if your engine code is p0421?
Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0421 code is combined with other codes, try fixing the other codes first.
What to do if you find a p0442 gas leak?
If you see a P0442 evaporative emission system leak detected code, you may be able to resolve the problem without much effort. The easiest solution may be to remove and reaffix the gas cap. Once you do, clear the code on the OBD-II diagnostic scanner and drive for a few days. If the code does not return, your gas cap likely was the culprit.
What does a p0171 reading on a catalyst mean?
P0171 or P0174 readings indicate too lean of a system in one of your cylinder banks. Learn common causes and solutions to these trouble codes. These trouble codes are both signs of catalyst efficiency problems. Learn what can cause these codes, and what to do about them.
When to use AutoZone’s OBD2 diagnostic tool?
Code Reader. When you detect there’s a problem with your vehicle, turn to AutoZone to help you pinpoint the issue. With our wide variety of code readers, you can get to the root of the problem in no time. Our OBD2 scanners and other diagnostic tools also help you keep track of your previous vehicle repairs. Next time your engine throws