cspak01

p0300 which are all my cylinders are misfiring.
p0301
p0302
p0303
p0304
p0420 could this code be making my cylinders misfire? 02 censor or CAT?
p0453 evap system high input

It Wasn't Me

How many miles on the car?

Any recent work done to it?

The P0420 is likely because the car is misfiring.

The P0453 is likely due to a leak of some sort. First, make sure your gas cap makes a good seal.

Also check the vacuum lines at the fuel tank pressure sensor. Make sure they're not cracked, disconnect, kinked, clogged, etc.

You should get one of these: http://www.helminc.com/helm/product2...C01&itemtype=N

cspak01

the car just hit 152k and i havent had any recent work done to it besides new coolant and new oil. I only misfires once in a while when i first start it up for about 5 sec.

neuhauser1

pull the plugs out and see what they look like.Also check for condensation in the boots. if thats not the case, reinstall and wet down the motor with water and see if it misfires. Its good to have a good baseline of checks. When i get a misfire the first things i do are
-check for good spark
-check for good fuel pressure
-check for power(first and foremost) but it sounds like there is power or it wouldnt start
-check compression

good luck

It Wasn't Me

Have the valves been adjusted yet?
Timing belt been replaced yet?
(if not, they're both overdue)

I would also run some Sea Foam through your system.

Have you tried resetting the ECU? (remove fuse #6 from the under-hood fuse box. Wait a minute, then reinstall)
Do that, then see if the codes pop up again.

Interesting.

You should get a scanner and check the freeze data, then post what you find on here. And, as previously noted, yes the misfire(s) can cause the P0420 Catalytic Converter code to pop up.


I'll see about scribbling together a DIY Troubleshoot for the P0453. In the meantime, I highly recommend you buy the manual I linked in my previous post. You don't have to buy a new one, there are used ones available online (ebay, craigslist, etc) as well as some used book stores. Check your local area.

It Wasn't Me

P0453: FTP Sensor Circuit High Voltage

1. Check the vacuum lines at the FTP sensor for kinks, cracks, leaks, clogging, etc. (under the car, behind the gas tank, on the driver's side, on top of the EVAP assembly)

Are the vacuum lines okay?

Yes - Go to step 2
No - Repair or replace the bad vacuum lines.

2. Reset the ECU. (remove fuse #6 from the under-hood fuse box. Wait a minute, then reinstall)

3. Remove the gas cap.

4. Turn the ignition switch ON (II)

5. Monitor the FTP sensor voltage with a scan tool, or measure the voltage between a body ground and terminal #14 (light green wire) of ECU connector E.

Wire side of female terminals.

Is there about 2.5 volts?

Yes - Intermittent failure, system is okay at this time. Check for poor connections, loose wires, etc. at the FTP sensor and at the ECU.
No - Go to step 6

6. Turn the ignition switch OFF.

7. Reinstall the fuel cap.

8. Disconnect the FTP sensor 3-pin connector.

9. Measure the voltage between FTP sensor terminals #1 (yellow/blue wire) and #2 (pink wire).

Wire side of female terminals.

Is there about 5 volts?

Yes - Go to step 15
No - Go to step 11

11. Turn the ignition switch OFF.

12. Disconnect ECU connector E (31-pin, as seen above).

13. With a jumper wire, connect FTP sensor connector terminal #2 to a body ground.

14. Check for continuity between ECU connector terminal E4 (pink wire) and a body ground.

Is there continuity?

Yes - Update the ECU if it doesn't have the latest software. (likely, it does) Or swap it with a known-good one, then recheck for the code. If the code doesn't come back up with the known-good ECU, keep it.

No - Repair the open in the wire between the FTP sensor and the ECU (E4).

15. Measure the voltage between FTP sensor connector terminals #2 (pink wire) and #3 (light green wire).

Is there about 5 volts?

Yes - Replace the FTP sensor.

No - Go to step 16.

16. Measure the voltage between ECU connector terminals E4 (pink wire) and E14 (light green wire).

Is there about 5 volts?

Yes - Repair the open in the wire between the FTP sensor and the ECU (E14).

No - Update the ECU if it doesn't have the latest software. (likely, it does) Or swap it with a known-good one, then recheck for the code. If the code doesn't come back up with the known-good ECU, keep it.

mnkimbrell

Im reading around bout the p0303 misfiring in the 3rd cylinder. I have changed plugs and wire also the fuel injector with no luck. Before all this happened i did a tune up myself and it ran fine for about a month before all this happened. what else could it be?

It Wasn't Me

These cars don't have spark plug wires. They have a coil pack for each cylinder. Are you sure you're posting in the right forum? What year is your car?

mnkimbrell

Yes im passive I have the right forum I have an 05 Honda civic LX SE 1.7. The only things I've done other than oil changes in the last yr was replace my cat. When I had it replaced it seemed like it had started to putter. So then I replaced the spark plugs w bosch plugs. After about a month it started misfiring on the 3rd cylinder. So since then I replaced the plugs again w nkg the coil spark boot and also the fuel injector on the 3rd cylinder. Not sure what else it could be

It Wasn't Me

A loose connection, or improper valve lash would do it.

What condition were the spark plugs in when you removed them this last time? Specifically the one in cylinder #3?

theblkrascal

p0420 is bank one..the CAT i have the same issue

GriFFIthS

I had P0420 for the 2nd time in 2 years, the first time i replaced the CAT, code went away no more issues till about 2 months ago, this time i removed the cat entirely and put in a 4-1 exhaust header, popped in a defouler on the secondary O2 Sensor and no more engine codes.
And yes im aware about emissions, but they dont check them here and i could care less, only time its ever an issue here is if you sell the vehicle and an inspection is order, the garage MIGHT make an issue with the fact the Cat is missing, tho hardly any ever do.

cspak01

Now im getting constant misfire from the time I start the engine. As soon as the car starts it begins to misfire and don't stop, the engine light just blinks continuously.

cspak01

Ran Seafoam and replaced the EGR and still have the same problem. i took a video of the automated system test. Not sure what some of the things mean but i noted:
Fuel System Status Bank 1 -Closed
Fuel System Status Bank 2 - Disabled
Fuel Pump Command - Low
Spark Advance - changing rapidly

The following was done while the car was idling.
http://www.youtube.com/watch?v=mjYGA0txJ-Y

Heres the link to watch full screen so you can see everything better.