I recently have been getting the P0420 code in my 4runner with CA emissions. Which means I have two catalytic converters. I took it into a shop where they took the voltage readings for the o2 sensors and they said it looked good. I was under the hood playing with the throttle while passing "Seafoam" through to clean the engine and noticed that some of that seafoam smoke was coming from in between exhaust pipes. The leak is at the connection right after the headers so I'm assuming it is just bad gaskets. I get the CEL P0420 code usually under hard accelerations, rainy weather, or stop and go driving. Unusual thing is that when I took it for a road trip from Portland to San Diego, and also from Portland to Seattle, the code never came on! Please help!!
Could a Exhaust leak cause P0420? on 1999 Toyota 4Runner
Asked by for the 1999 Toyota 4Runner
This week's top 10
Recent Toyota 4Runner Questions
- How to kill VSC OFF, VSC TRAC & ENGINE lights that stay on?
- Abs light n alarm sound on constantly can't drive vehicle brake don't work
- Vents blowing cold air.engine stops, I put water in the radiator and it runs out
- ABS control module p/n 8954035270 replace . Is it need to programmed by dealer.
- vsc trac off/vsc off lights turn on when I put it in gear.How do I putlights out
1999 Toyota 4Runner Estimates
- Wheel Bearing Replacement - Front ($398 - $634) in Ho Ho Kus, NJ
- Door Window Motor Replacement ($220 - $532) in Klamath Falls, OR
- Mass Airflow Sensor Replacement ($251 - $946) in Nemo, TX
- Coolant Leak Diagnosis ($88 - $111) in Postville, IA
- Wheel Speed Sensor Replacement ($371 - $1,931) in Lamar, CO
- Wheel Speed Sensor Replacement ($292 - $354) in Fairview, IL