Hello

Recently I was on holiday for 2 weeks, during that time MIL turned on
2 times but after about an hour driving it was going off, on the way back
home the MIL turned on again so I decided to take the car (Honda Civic
2001 1.6 VTEC UK version) to the nearest dealer to have that checked.

I left the car with them last tuesday 06-01-2009 and this afternoon
15-01-2009 they called me so I could get the car back as everything is
sorted now.

So I got invoice for 207.00 GBP with works done:

"With HDS found codes P0171 fuel metering too lean P0420 cat system
effciency below threshold checked no 4 10A fuse under dash OK. checked
fuel pressure OK (32- KPG at idle and 3000 RPM) checked oxygen sensor 1
with HDS found sensor opearation OK. applied vacuum to evap canister
purge valve"

"Intake side, vacuum held OK checked MAP sensor with HDS IGN on
atmospheric pressure indicated OK advice valve clearance check"

"checked/adjusted valve clearances, deleted codes road tested for approx
11 miles OK"

As I dont know much about cars I was happy to pay that price as long as I
had the problem behind but apparently I was wrong as after 2 miles I got
the MIL back ON, I was frustrated, I went straight back to the service and
they couldnt tell me anything, they wanted me to leave the car once again
with them but as I didnt want more expenses atm I said I need the car
over the weekend and they want me to bring the car at monday but I am
afraid they're just trying to get more money of from me.


Can anyone give me some advice or help please, any ideas or give me
direction where and how I could get ready myself for the next visit at the
dealer.

Thanks.

 

Pretty sure "cat system efficiency below threshold" means you need a new catalytic converter. Not sure why they checked O2 #1, but not #2 with the cat code in there.
Seems to me the secondary O2 is reading rich and the car is pulling fuel out to compensate... which is throwing both codes. Im willing to bet the cat is the problem.

 

Thank you, does anyone know how much will cost me changing the cat at the honda service ?

 

HAHAH..do not go to the stealership..they will charge you out the ***...just search and get a high flow cat..you can get a good one for around $200...if not stealership is going to charge you over $500

 

replace your o2 sensors. your car is fine.

 

I will be going to dealer at wednesday and I will try to convince him to replace O2 sensors first and see if that fixes the problem then. I may as well try to read about replacing that sensors and will se if I am capable of doing that myself.

Thanks for advice.

PS. I am just back after 50miles trip and there is nothing wrong with my car that I can feel except of course that engin check lam witch haunts me.

 

oooooooooooooooooooook. Looks like the tech did everything on par. If I were working on the car i would have inspected the coil-on-plugs and spark plugs before adjusting valves. At any rate first, get the code scanned at an auto parts store. if p0420 returns (cat 1 efficiency) returns, you will need a new cat. aftermarket cats, from my experience last around 2 years, if that- which is long enough for you to get 2 or 4 years worth of tags for your ride. if p0171 returns you're looking at more work, in which case return to the tech who worked on it previously. ive often seen coil-on-plugs fail in 01-05 civics. If both codes return, troubleshoot the p0171 first. its possible that code could trigger the 420. also, how many miles are on your car? have you replaced spark plugs at all? i would not recommend throwing h02 sensors at it, especially aftermarket ones in a honda, if your troubleshooting has not led you, or the technician to that conclusion. Hope my insight has helped here...

 

are you serious? this is a classic case of typical denso o2 sensors starting to go out on a honda. Especially since its throwing both p0171 AND p0420 together. Throwing a new cat on this car would be the bigger waste of money. COP engines go through o2 sensors in higher frequency than spark plugs. Average life of COP operated spark plug: 100K+ miles, average life of o2 sensors: 60K miles. I see this problem at least once a week, my money is on o2 sensors.

 

Car is on 85K and at 80K I had plugs replaced during service.
I am just waiting for OBD2 reader and then I will be able to give you some more information witch code is coming first and eventually if there are any freeze frames. Ive lost confidence in my dealer so I have to check it myself I guess.

@skipbarber
"checked oxygen sensor 1 with HDS found sensor opearation OK"

Can I believe it?
This is what I found on the invoice from the dealer who investigated the problem in the first place, the full list of things what he did are in my first post.

EDIT:
Yesterday I've done 150miles getting my friend parents from airport, there was no sights of any problem with a car except MIL on, if that helps.