Rep Power: 0

For the last couple months I've driven my car- no check engine light, no issues. Then..this last week has given me these two codes, twice AND only at the same time.

I have researched these codes... which doesn't give a result that matches my actual issue.

The P0706 code reads:

Faulty Park/neutral position switch
Misadjusted park/neutral position switch
Park/neutral position switch harness is open or shorted
Park/neutral position switch circuit poor electrical connection


The P1456 code reads:

Missing Fuel cap
Incorrect fuel filler cap used
Fuel filler cap remains open or fails to close
Foreign matter caught in fuel filler cap
EVAP purge control solenoid
EVAP canister Fuel tank pressure sensor

1999 civic coupe AT (im sure someone will ask)

That said- I can drive the car fine. No weird speedometer jump. No locking into "limp mode". No chugging. No unusual sounds or smells. The only issue has existed for a couple months- which I believe is a small slip, which should be getting fixed thursday. Outside of that I don't know what else would cause these two codes to pop at the same time. Any ideas?

 
Rep Power: 518

What year is the car?












Ok...which engine is in it (engine code, vtec or not, etc.)?

Check your code reader again. P0706 is not for that car.
There's a P1706 in my list but not P0706. Try a couple different readers?

P1456 is a leak in the tank system.
Are you in the rust/salt belt? (yes) Do you ever smell fuel in the garage?

 
Rep Power: 0

When I back into my driveway and get out I get a hint of gasoline smell. Its about the same strength to it, as if you had a drop of gas on your hand.

I have used 2 different readers - and gotten the same P0706 :-s

 
Rep Power: 518

Wellll, that P1456 code probably is accurate then.
Is the smell worse after you fill the tank? Have you looked underneath to see if there's stains on the tank....drivers side and rear seem to be where I've seen them rust out here, along with brake lines and fuel lines.

IOW see if you can tell where that smell comes from first. Pinhole in a hose underneath (does not have to be a liquid line, could be a vapor line),, pinhole in the tank, rubber gasket on the fuel cap weather cracked, something along those lines. Could pull up the back seat and check in the access covers too.




For the P0706 code I'm looking at 1706 info....I'm assuming here, it's the best I can do LOL

Does the D light on the PRNDL display work?
Does D stay lit up while your shifter is in Drive? (might need to erase codes first)
Do all those lights light up for each corresponding shift lever position?

If you move the shifter back and forth in the D position slightly, does the light flicker or go out? (possible poor switch contacts)
If the D (D4 actually) switch goes open circuit and stays that way long enough, the PCM detects a fault.
Possible cause might be if the shift cable isn't adjusted right the switch might get hung between 2 sets of contacts and makes the PCM lose the D signal, then the PCM gets confused...... or if the switch contacts are worn badly the D switch could make intermittent contact.
I believe if the code is true then you should be seeing the evidence happen on the dash as you drive while watching the D light.
Note that after the code has set, the CEL turns on and the D light will probably stay off since the PCM has control of that light.

I have seen similar faults set when someone used the shifter as a hand rest and pulled it just far enough for the light to go out....just to give you an idea.

Have you erased the codes, then recheck to see what returns immediately?
How quick do you get any codes returning?

 
Rep Power: 0

Will check for staining tomorrow.

I did check the gas cap yesterday when I filled up- the o ring is shot. They are 10 bucks. Figure I can start with cheap fix before I dump 160 into a new purge valve.

As for lights for the gears, on the dash it I haven't noticed any flickering or anything of that nature HOWEVER I do catch myself resting my hand on the shifter- bad habit I know. The console lights on the shifter used to work- but haven't for a bit. I could check those out aswell- bulb might have burnt out?

Codes were cleared lastweek, came back about 3 or 4 days later-ish (about 100 +/- miles? )

 
Rep Power: 518

Light on the shifter console should be just a simple tiny bulb.
The PRNDL display on the gauges is the one to be watching for problems.
Still hard to say because the P0706 code isn't supposed to be possible on that car.

Do you have your own code reader?
Will your code reader show pending or temporary codes? (code in progress, fault detected once and waiting to see if it happens again before turning on the idiot light)

I'm thinking it takes a few days because the evap code has to fail in each of two consecutive drive cycles before it will turn on the light (very specific conditions must be met before the self test will run)

But yea fix the obvious gas cap first and erase the codes before going any further, then see if codes return later.

 
Rep Power: 0

Same codes here on a 2000 Civic EX D16Y8.

Not sure how the op is doing but bench testing the evap purge control solenoid with a 9v battery shook it loose and fixed the p1456. The cel did not clear itself, I had to clear it manually, about six drive cycles ago.

As for the p0706 (AutoZone, CA. code reader), I sometimes have to push the shifter forward towards P to start the car but it never set a cel. I only saw the code for the first time while chasing the evap cel. No repair needed here.

 
Rep Power: 0

Been a couple of days, armed with a new gas cap with about 1 to 2 drive cycles And... I'm keeping my hand away from the shifter (a serious conscious effort!)

no !!! Good stuff!

The O ring was a bit... worn. The cap itself has the original "Honda MFG" label.

 
Rep Power: 0

Guess I should rethink saying they don't match whats wrong- because one did.

Now to figure out my next move with the transmission- The trans shop said the magnet had a good amount of debris on it- when they did the service. Will start a new thread about that. Stay tuned

 
Rep Power: 518

Whut?

Magnets always collect a bunch of debris in the transmission that is normal, and the longer it's in there without service/cleaning the bigger the clump of hair you will find stuck to it.
If there was SOLID chunks of gear or bearing stuck to it that would be bad.