2005 Nissan Sentra. code P0420. Tried the laquer thinner tip and it worked. Now every two to three gas fillups, the light would come on and off. The dealership said the particles in cat can enter the engine and damage it. Is that true?
Not really if you think about it. You've got a a catalytic converter which is on the exhaust system. The hot gas comes out of the engine in the manifold and then goes through the exhaust system to the catalytic converter. Pieces from the catalytic converter cannot get inside of the engine because the pressure is blowing it in the opposite direction.
The only thing that can really happen with that is, if the catalytic converter pieces do break up, they could go further down the line and they might clog up the muffler. I've seen the ones that were really worn do that. Pieces from the catalytic converter break up and then go on and jam in the muffler. Then the car doesn't run right, and when I take the muffler off, I find that it is jammed and packed full of catalytic converter pieces. Then you've got to replace the catalytic converter and the muffler. But it can't get into the engine because they flow is in the opposite way. You may want to have the Check Engine Light checked to determine what repair is needed.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%