NP bro, go on youtube and watch Scotty Kilmer's stuff he is awesome.

I am putting a can in myself soon to do a cleaning. Do it every 6 or 4 months.

 

300 miles and yupp.....SES turned ON.

I am replacing CAT.......gas mileage dropped too......telling me CAT has gone or going out.

 

Time for some high flow cats

 

Strange…….SES came on for P0420 after 300 miles. I was scheduling to replace CAT. Now after 350 miles SES went away and it's been off while I am getting close to 400 miles.

This damn thing is like…… go and replace CAT……no wait……OK go ahead…..No but wait.

I am not sure about exhaust leak so that will be the first one I will have to check again before ripping apart my CAT.

 

Further update......just in case anyone try to chase the tail like me. Within few days I started hearing rattling......it only appears under acceleration. The noise is like a marble in bucket. And no this is not an exhaust shield broken off issue. This is the point where anyone should STOP driving car immediately. I am waiting for shop to arrange CAT replacement schedule.

 

Just to update on this case. I had magna flow cat replaced and P0420 was long gone. It's almost 500 miles and no p0420 code being appeared so far.

 

So I know that this thread is old. I actually just bought a used 2015 Maxima but I'm here because I had a question on the P0420 that I got on my 2008 Honda Pilot with 160k miles. CEL came on one day and I stopped by AZ and they gave me this code. Tried to sell me Cataclean but I did not buy. I went home and plugged in my scanner and same code came on. I reset it and about 200 miles later it came back. My friend who is a tech at Acura dealer said the cat needs to be replaced. He said if it was the sensor it would have thrown a different code at me. I saw Scotty's video but was hesitant about what the thinner can do to the fuel system even a lot of people have said they used it and I have not read of anything negative. It either worked or it did not.

Was wondering for those who have used it whether you have seen any side effects from it after this last 4 years went by. I guess I can try it as the vehicle is fairly old but it runs absolutely great and I just hate to have the thinner do anything to harm the vehicle therefore I am hesitant. Thanks for any feedback.

Vince

 

My Nissan maxima 2006 is showing P0420... I did the lacquer treatment with no luck and changed the downstream O2 sensor. I just got the Bluetooth obd2 reader and here are the results...pictures inserted. Thanks for any help.

 

Hello, hoping to get some info without creating a new thread. I have an 08 SL with 168k miles and have a P0420 code. Car runs well other than some timing chain noise when its cold. My question: is there more than one bank one cat? Is there a pre cat off the manifold, then the y pipe, or is the Y pipe what needs replaced? Or both? Hoping to do this in my garage. I've read it's possible as long as the bolts dont snap. Please advise. Thanks yall