Miller219

Hello,

I am experiencing poor fuel mileage and a backfire on the lower rpms.

I did a Diagnostic Scan on my 2003 Honda Accord
The following codes came up

P0135
P0453
P0498

Any thoughts on this?

KWayRacing

P0135 = Potentially faulty primary 02 sensor.
P0453 = Feul tank pressure sensor high voltage
P0498 = EVAP Canister Vent Shut Valve Circuit Low Voltage

My recomendations
For 135 Clear code if code instantly/ CEL comes right on(5-10 seconds) after clearing then replace primary 02 sensor. Clear codes again then.
For 498
Check for a poor connection of the LT
GRN/RED wire on connector C501. BTW C501 is is the 20 pin white connector located directly left of the DLC. You should be able to see it with the lower left dash panel removed. The first 3 wires are light green with a red stripe look at these wires closely making sure each one is connected securely to the connector from both sides of the connector and repair if needed.
If no repair is necessary then I would wait for the codes to return and then either diagnose it myself or take it to a shop which is competent in Evaporative emissions repairs.
Hope this helps.

biggdogg

i get these all the time in the shop. replace gas cap, and secindary o2 sensor. should take care of it no problem.

Tmac06

Instead of making a new thread, I'll hijack this one

My emissions malfunction lamp came on while my wife was getting on the highway with heavy acceleration from 40 mph - 65mph. It flashed, then stayed on, but once she slowed down to about 45 it went off. When we duplicated the results the following day, the light came on and has been on for the past couple of days.

I ran a code reader and got:
P1301 Misfire on Cylinder 1
P1305 Misfire on Cylinder 5
P1300 Multiple Cylinder Misfire Detected

I tried researching the problem and it seems like it could be endless, I figure to start with the plugs and go from there. I'm no mechanic by any means, so my plan B is to take to a shop for a full diagnostics.


I'd appreciate any tips for where to start or what the most common issues are.

I drive a 2005 Accord V6, with about 97,500 miles on it.

Thanks!

briq4

x2 with Tmac02. Exact same issues, and VERY random, can go for months without seeing ita gain.

KWayRacing

THere is a software update for this. This is quoted directly from service bulletin 08-022
SYMPTOM
The MIL is on with DTC P0301 (No. 1 cylinder misfire
detected) and DTC P0305 (No. 5 cylinder misfire
detected). DTC P0300 (random cylinder misfire
detected) may also be stored.

PROBABLE CAUSE
An incorrect CKP high-speed learned value may be
stored in the PCM after battery power is disconnected
and reconnected to the PCM/ECM. This can cause the
PCM/ECM to misinterpret the CKP input as a paired
cylinder #1 and #5 misfire.

CORRECTIVE ACTION
Update the PGM-FI software with the HDS.

Hope this helps.

Tmac06

Thanks, seems like it could be helpful. I disconnected the battery about a week before this happened to replace the headlights.

How do I get the update?

EDIT: I spoke with my dealer and he said that the Software issue will normally spit out a bunch of random codes that won't necessarily make sense. He also said to try and run a fuel injector cleaner through a tank or so of gas and bring the car in for a fuel system flush ($109.99), he said the cylinder misfire has been a common issue lately most likely due to some lower grade gasoline making it through the area.

I'll be running a fuel injector cleaner as well as hopefully getting around to checking my plugs this weekend.

I've noticed that the fuel grades are different, when I was back in VA the minimum octane grade was 87, where as here in MT it's 85. Not to mention I buy most of my gas at Sam's Club (which I've heard mixed things about) and if not there, then on base, which probably isn't the highest quality fuel either.

KWayRacing

Fuel system flushes are a bunch of junk. 110$ spent on nothing. Ask your dealer if this fuel system flush uses any Honda products. It doesn't because Honda as a company doesn't recomend ANY flushes. This statement comes from a Honda published service news dated February 2006 page 4.
"In Honda vehicles, the transmission, as well as the
systems that handle lubrication, cooling, fuel, and
power steering, are designed to give thousands of
miles of trouble-free service if you follow the
maintenance schedule to the letter.
Flush systems are a popular aftermarket offering
these days. These products look impressive and
make lots of claims, but American Honda strongly
recommends you avoid using them on any Honda
vehicle......"
You should ask your dealer about this and just see what he says. You should be able to pay a fee for a PCM update. Somewhere between .5 hours and 1.0 hours labor would be a fair price. Hope that helps.

Tmac06

Thanks for that info. That's pretty interesting, especially at $110!

So then on a side note, if the flush is junk, is it worth running a "Fuel System Cleaner" through a tank of fuel?

I appreciate the added info you provide with these service bulletins, especially with the dealer rates at somewhere around $90.00/Hr.

KWayRacing

The occasional of a fuel system treatment such as Techron, STP, whatever,IMO, can not hurt. I use Techron somewhere around once a year. I also always use a top tier fuel though. Top tier fuel reduces the need for these additives. Here is some interesting reading. http://www.google.com/url?sa=t&sourc...yDtsR7jHJRBayw

jdeemseerx

actually your wrong honda does make a top engine clean and also had maintenance intervals for brake fluid along with power steering fluid.. with that said to fix the codes i would just get the pcm update it is common.. forget about the injector service

austumpy01

I'm having the same problem as TMac06. I was wondering if there has been an update to the problem.