How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask ase_master327 Your Own Question
ase_master327, Shop Owner
Category: Toyota
Satisfied Customers: 5288
Experience:  +15 years experience with Toyotas. Bumper to bumper diagnosis & repair.
Type Your Toyota Question Here...
ase_master327 is online now
A new question is answered every 9 seconds

Engine code 442 with check engine light on. Any ideas got

Customer Question

Engine code 442 with check engine light on. Any ideas? got the code from auto zone but they are not much help with diagnosis. car has 110k miles and is an o4 corolla
Submitted: 6 years ago.
Category: Toyota
Expert:  ase_master327 replied 6 years ago.
Hi, thanks for asking.

This is one of the hardest codes to try diagnose on any car.. This means EVAP system.. SMALL leak detected.. Normally you would hook a smoke machine to the EVAP system and activate all the relays and valves with a scantool to see if there was any changes, etc, etc.. this is something that is going to havve to go to a shop for 99% of the time.

Anyways, if yu have access to the proper testing equipment or know someone who does..... I can put the diagnostic steps together for you.. just let me know if you need them. As far as what it will cost in a shop.. Diagnosis is usually about $100 and then if you hiore them to do the work. SOMETIMES they will knock the diagnosis price off the end price if it exceeds the cost of diagnosis.

Anyways.. If I have been helpful so far (letting you know what the code meand and what to expect), then click Accept so I can get credit for helping you. After that, if you need anything else, just let me know. Fair? Cool
ase_master327 and 4 other Toyota Specialists are ready to help you
Customer: replied 6 years ago.
I am told I made an error. the code was 420. I will of course accept your response and make the payment. Thank you
Expert:  ase_master327 replied 6 years ago.
Ohh.. ok.. well the P0420 code does change things, and is probably the reason they sold the car. THAT code means the catalytic converter is having problems.... according to the rear 02 sensor..
Common causes for this code are.. bad catalytic converter.. Rear 02 sensor problems, engine misfires and exhaust leaks. Exhaust leaks being the most common.

Of course.. the 'proper' diagnosis still involves a scantool to monitor the signals from the 02 sensors.... IF.. there are no exhaust leaks.

You can check the converter by hitting it with a hammer to see if the 'stuff' rattles around in there.. and if it does.. then you need a converter.

I can send the 'proper' diagnostic for that too, if you need it.. and of course.. I will still be here if you need anything else.:)

Related Toyota Questions