Hello The Check engine light comes on after being reset. Then after the 38 mile drive of 15 street and 15 highway to activate the 8 emission sensors in the computer, Another 8 miles after the Check engine light came on and 2 codes popped from the AutoZone Free Checker. P0420 - Catalyst System Efficiency Below Threshold B1 P1457 - Evaporator Control System Leakage (Evap Canister Area) Looks like it maybe as simple as a Evaporator Canister or Hose or a very expensive Catalytic Converter?? Anyone have this problem and a what needed to be fixed? 1-2 - AutoZone Check Engine Light Analysis 3. Check engine light on in dash on far left. 4. - Honda Car Engine 5-7. Checking the computer codes with AutoZone Self-Check Analyzer Car Code Dump Procedure with AutoZone Self-Check Analyzer 1. Pug in Analyzer 2. Start Car 3. Wait until analyzer display reads "done" 4. Turn car off 5. Unplug analyzer Bring back in store and get printout of the code dump with list of parts causing the problem. Someone else has a Honda on the Internet with the same 2 codes just like this car! P0420 and P1457 - Honda-Tech - Honda Forum Discussion
Does it have an 02 sensor on each side on the cat(s)? Could have a lazy sensor giving a false/weak reading. Evap leak is often bad gas cap.
Thanks so much, we will check that. Here is more info too! Someone else has a Honda on the Internet with the same 2 codes just like this car! P0420 and P1457 - Honda-Tech - Honda Forum Discussion From the link above. P0420 is set when the secondary oxygen sensor signal suggests the catalytic converter is no longer functioning sufficiently. It is highly unlikely that there is a sensor or wiring failure as the criteria for this DTC is such that the secondary oxygen sensor data must closely resemble the primary oxygen sensor data. This is hard to reproduce with a sensor or wiring fault. The problem is likely a contaminated catalytic converter. Replacement is necessary. The P1457 is an EVAP DTC, as you are aware. However, this DTC is for the canister portion of the system rather than the fuel tank portion. A faulty fuel cap will not cause this DTC. The system complexity MAY require you pay a qualified technician to diagnose. So it does look like a bad Catalytic Converter!!! Not the gas cap. Since that will probably fix the first code then the second code may also clear up? Always do one part at a time right?
Don’t unknowingly over analyze it. O2 sensor is getting lazy. Canister purge or vent is failing, smoke test it. Evap is evap. Does not care where. Gas cap seal is a big failure. If you fill the gas with engine running it sets a fault under a vacuum test. These are simple problems. These are totally different problems. These are easy fixes.
Evap problems don't generally affect how the engine runs at all either...just kicks that annoying light on! The 02 sensor however needs to be replaced (if that is indeed the problem) it will affect efficiency at first, but can cause some real issues further down the road! And you really never know when that day is gonna come either...
If you are one of those that like to top off the gas tank after the unit stops - it is the evap system - canister- it is contaminated with raw fuel. Some of those systems - canisters are cazy expensive. as to the O2 sensor a more in depth look will be required. They due fail but 50% of the time it is the wiring harness that is the culprit. Gas cap is cheap and they due go south seal wise. Whether the 2 are related I can't say.
At 168k it’s quite possible you have two problems. Cat failure is quite possible. The evap code could be a valve that gave up the ghost or a corroded wire from the pcm. It is a simple 2 wire circuit. With a wire diagram find both ends of each wire and perform a loaded voltage drop test. If the wires test ok I would replace the valve. Slight chance it’s the pcm but I like to rule out the wires and component before replacing the computer. Vent valve opens to let air into the fuel system so the vapors can be burned in the engine. Shouldn’t cause issues with the exhaust.
Just found the receipt on the last catalytic converter replacement at that time under warranty was June 25. 2019 so not quite a year old! Hope it is not that again!
Yeah I guess I didn't word my reply very well...I guess I should have said evap leaks wont generally cause running problems...small to medium leaks...like bad gas cap seal, etc. But purge valve hanging open is a large leak, no?
Kinda splitting hairs but, I guess it would depend how open it was staying. I Wasnt familiar with that code but after some reading it isn’t necessarily pointing to the vent valve just saying there is a leak. At this point I would perform a smoke test and go from there. Unfortunately not really a “in the driveway” type test.
I run this stuff through my cat once a year to help keep it clean. (link wont work ) CRC Guaranteed to Pass Emissions Test Formula I get the evap leak code a lot, usually not long after I fill up the gas tank and the attendant might not of put the cap on correctly. O2 sensors on my 4Runner were an easy DIY job that I did about 8 years ago and havent had any problems. I hope its the same for your Honda. You can those find parts on Amazon also. I also changed out the pcv valve 2 years ago. Most of the codes that have popped up on me were just annoyances.
. There are 2 - O2 sensors the upstream and downstream We just replaced the downstream O2 sensor After clearing the computer we will have to run through the sensor exercise drive pattern to see if that fixes it.
Last night we took the CRV out for the 19 mile city and 19 mile highway. I believe it takes 35 miles to reset all the computer sensors then if there is a problem then 3 more miles to trip the sensor. Well no check engine light so, it looks like it is fixed. If not I will post again. Thanks all for your suggestions.
The whole purpose of the car computer is to read the 8 sensors That monitor the emission controls. The 2 Engine check codes that popped were bad catalytic converter or bad evaporator canister. The codes are setup only to give the device description that could be faulty if one of the sensors detects a fault. However if an emission control sensor is faulty the computer does not tell you that! In this case since the catalytic converter Was replaced less than a year ago and is good, then one bad sensor such as one of the 2 oxygen sensors can be the culprit. Since the upstream O2 sensor measures the mixture of the air and fuel to adjust the flow of the gas, it is more likely to be the downstream O2 sensor which monitors the exhaust gases that flow out of the catalytic converter. We the check engine light is no longer on after clearing the computer and driving 19 miles city and 19 miles highway to reset the computer and trigger a fault if there is still a problem.
