Shaunybo1

I have an 02 Civic EX automatic and just yesterday I was going about 65 mph and I had a hard shift and my CEL came on and the D light started blinking. I went to Advanced auto parts and got my codes pulled. Here they are.

P1457 EVAP Emission Control System Leak Detected (Control Canister System)
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0720 Output Speed Sensor Circuit Malfunction
P0730 Incorrect Gear Ratio

I've done research on them, and my main question is would is there a way to find out if the P0720 would push out the code P0730 or did my transmission just take a crap? I have been babying the car since it happened, but if I give it some gas, my shifts are hard(revs over 500 rpm prior to shifting, thus is not a smooth shift). Id rather not have to buy a new gear box, but if I have to I will, if there is not a way to tell the difference, would it be worth it to replace the VSS and see if that fixes the main issue?

I'm assuming the EVAP errors are pushed because of a bad CAT and I assume I'll have to replace that as well. Any input would be much appreciated.

EDIT: Also the car has 150k miles on it, I know that's relevant.

Shaunybo1

Over 100 views and no replies? No one had this before?

toyomatt84

iTrader: (1)

This means almost nothing these days. Sites like Google and WebArchive use site caching bots to store page data of websites to make them accessible if the site ever goes down. These bots account for 80-90% of thread views on a forum like this.

As for your problem, you'll probably want to address the EVAP system related errors first. I'd recommend inspecting for exhaust leaks, and then moving on to running some SeaFoam through the system to clear up any carbon deposits. If you're still running into issues, get the Oxygen Sensors tested/looked at. If they're faulty, replace them. If not, then you're sadly looking at replacing the catalytic converter. Magnaflow makes a bolt-in replacement that is slightly superior to the factory product, and can be quite a bit cheaper through companies like RockAuto.

Then, to address the transmission issues, I would advise having a transmission fluid change, driving 3,000 to 5,000 miles and changing the fluid again (to try and remove any debris in the transmission). Use factory Honda transmission fluid. If problems persist, you may need a new transmission.

Shaunybo1

Well thank you for the reply Matt, I will definitely look into that. I already ordered the VSS, since it was the only thing I had to go on based on what little I know about these particular issues. I'll go ahead and replace the sensor, inspect the exhaust, and run some seafoam through it, and of course getting the fluid changed.

After the fluid change, should I notice a difference in the "roughness" of the shifts if there is in fact debris in there? And then again the in 3000 to 5000 range.

toyomatt84

iTrader: (1)

After replacing the fluid in the transmission, you should definitely notice whether or not it has had any impact on the car's shifting ability. If there's little to no change, then you're looking at internal damage and possible need to replace the transmission.

Shaunybo1

UPDATE:
Ok so I got seafoam ran through the entire system, and went ahead and replaced the spark plugs while I was at it, and replaced the ATF fluid and added a small amount of ATF seafoam while I did so. When I went to replace the VSS, I noticed the wires going to the VSS wear completely twisted on the bracket that held them and one wire was completely torn, I then cut back and spliced the wires back together and noticed the VSS I ordered does not fit the harness on my current one, leaving me to believe the previous owner had done something to it, its a two prong, where as the one I ordered for the stock one is a three prong. So after doing all that, I just put the old VSS back on.

The car still shifts hard, but not as bad. I went back to the parts store and had my codes pulled again, and now I only have the one code P0720 Output Speed Sensor Circuit Malfunction. Which I assume is a great leap, seeing as now the ECU isn't pushing the incorrect gear ratio code or the cat or emissions codes.

I'm going to find a VSS that fits that harness and replace it, and if the shifts are still hard and the ECU is still pushing the code, I will try to find a way to replace the wiring going to the VSS.

EDIT: Also noticed quite a bit of small metal debris on the end of the drain plug on the transmission, it was like a grey goo of tiny metal debris that was magnetized to the end of the plug.

toyomatt84

iTrader: (1)

I'm glad to see you're making progress... but in the same mind, I'm sorry to see that you're finding more problems. Judging by how much metal was in your transmission fluid, I fear the worst. But, its nice that you got it to shift somewhat smoother. I would definitely say that finding the correct wiring for your VSS to function properly, would be ideal. That way, down the road, you can always have a factory plug to work with.

Shaunybo1

UPDATE:
So after mindlessly trying to find a VSS that would fit, only one I found was on ebay. I also confirmed I have a CVT transmission to make sure it was the stock one and all the part stores have the three prong VSS and none of the two prong. So I found a diagnostic diagram to make sure the VSS countershaft and mainshaft were good, measured the resistance on both and both showed between 400 and 600 ohms of resistance, so both the VSS's are good. So I must now move on to find a short or open in the system by checking the PCM connectors. I'll post another update probably next week with my findings.

toyomatt84

iTrader: (1)

You have a CVT? I was unaware that CVT's came on the EX. I'm pretty sure they only come on the Hybrid's and GX's (Natural Gas engine).

Shaunybo1

I'm going by what I was told by vendors, if I'm wrong please enlighten me. Doing more research now.. lol. Is there a stamp on the trans that I can look for? I saw the stamp on the engine for the D17A2.

It has to be the 4 speed automatic eh? Is there a model on that?

toyomatt84

iTrader: (1)

If memory serves me right, there's a tag riveted to the bellhousing of the transmission. Its nearest the front of the car on the topside, right next to the engine block.