Anyone here know anything about cars?

[1987_Lakers]

I got a fuel injection cleaning a couple of days ago, but right after I got it my check engine light came on, I got it checked and the code po420 came out. I took it to a mechanic and he said I need a new catalytic converter (God I hope not). I did some research online and found that most people who had a check engine light come on after a fuel cleaning turned out to be the 02 sensor was the problem (also triggers a po420 code). Any mechanics on ISH?

[TheReal Kendall]

Get it looked at again and then fix the sensor. If it still says the same thing then it might be the converter.

What kind of car is it? There's a lot of forums online now with great info

[Crown&Coke]

I'm no expert, but does your check engine light come and go?

When my o2 sensor went bad my check engine light would pop up, then go away when I shut my car off and restarted it

I would change the o2 sensor first either way

[JohnStarks]

It might help if you posted the model and year of the car unless its a Ford, I wouldnt drive a ford if it was given to me for free

[1987_Lakers]

05 toyota corolla

[moaz]

I got a fuel injection cleaning a couple of days ago, but right after I got it my check engine light came on, I got it checked and the code po420 came out. I took it to a mechanic and he said I need a new catalytic converter (God I hope not). I did some research online and found that most people who had a check engine light come on after a fuel cleaning turned out to be the 02 sensor was the problem (also triggers a po420 code). Any mechanics on ISH?

Pray for you.

I had to change 2 of the 3 cat converters on my Mazda Tribute last month. It was $1800 CAD with huge discount form my mechanic. The 2 parts alone would have been $2700 from Mazda.

I had also the engine light on one Thursday but since we had a very bad ice storm I thought I could wait till the weekend to fix it. After a snow bank encounter on Friday, the car wouldn't go more than 50 KmH. Daamn, the converters looked like burned coal when they took them out.

[nathanjizzle]

yes op. The catalytic converter has a sensor in it to gauge exhuast. you could have clogged the o2 sensor or the combs of the catalytic converter itself by using the injection cleaners. In that case, youll need a new one. i think the cost is around 400-500 to replace one at a shop.

you can try to disconnect the battery, put the key in the ignition and turn it on to drain the remaining power. then connect battery and turn it on again to see if the engine light is on or off. i think this would work because typically injection cleaning exhaust will only last untill your gas tank has been emptied of it (if you used an additive.) use fresh gas, reset your diagnostic system by the way i just explained

[PHX_Phan]

Reset the computer and see if the code comes back up. It could be nothing, could be a sensor, could be the cat(s). The converter will be pricey, no way around that.

There's also the not so legal method of cutting out the cat and removing the codes with a scanner. It's a Corolla, and they most likely won't crawl under the car for a visual inspection. I took them out of my last car.

Edit: Could also be the MAF sensor. Pretty much, if you're reliant on someone else checking all these things, you could be facing some headaches.