Hi Everyone, i just smogged my car and sadly it failed.

Readings...


1998 Honda Civic EX. All stock.
New Oil/filter change, new cap & rotor.

Please help. Thanks in advanced.

 

looks like your cel was on? perhaps o2 cel? saying your cat has gone bad?

 

It was on for a couple days before. I checked the code and it was for a misfire, but didn't say which cylinder. Basically a random. I deleted the code before taking to smog station.

Any suggestions?

Thanks.

 

looks like a bad or gutted cat to me causing your ck engine light shouldnt be too expensive!

 

sorry didnt see ur last post ck ur pugs and wires

 

I never gutted it, but being a 10 year old cat maybe its time to change it. How often should the cat be changed?

 

i just saw high hc which is raw fuel so the misfire sounds right plugs and/or wires is first step

 

my 2000 civic failed with the same, but higher failed readings.
For me it was my Cat, needed it fully replaced, cost me about $325, due to it being in the front. >< that was a shock, the other hondas i had costed about 60-70 to replace, 87 accord hatch, 88 civic std. depending where you go, you might have to notify them ahead to get the part. These cats are junk, from what i read and hear, so more likely it.

As with everything, thats my 2 cents, you might have different problem

 

Ok, heres the deal. Our shop test for emissions, and what we've seen over and over is you cannot delete the CEL before getting it tested. There is a certain amount of trip cycles it goes threw which are called *readiness monitors*

thats showing that you have a check engine light on, and dont replace the 02 sensor quite yet. pull the codes and figure it out, and dont just hang random parts meaning giving your car a 'tune up' because you have one plug thats bad. it might not even be a plug, could be an injector or bad wire. Any questions e-mail me at theboss8907@yahoo.com

 

i would start with check your cap and rotors / spark plugs etc a tune up is sometimes what you need but sometimes you need to check the datalist with a scan tool to see if the secondary O2 sensor response time is not slow. would also check the fuel tirm.
if the response time is slow then that could cause a rich mixture also

 

Well I did reset the CEL before the test. YEsterday afternoon the CEL lit up again and i got 2 codes. First is P0171 "system too lean" and the other is P0170 "Fuel Trim Malfunction." Searching the net about these codes, I am still not 100% clear of what to do. Some people say the vaccum lines has a leak others say fuel pressure regulator is bad. i am totally confused. i plan on bring it into Honda to have it check and estimated. Unless someone can help me remedy this and hopefully I can do it myself.

Oh, I already changed my cap and rotor and also my plugs.

Thanks in advanced.

 

p0171- fuel system is lean, so your ECU is dumping tons of fuel to compensate for it.

Hook it up to a monitor and check your values....STFT and LTFT(short/long term fuel trim) values.

Make sure you have good ignition parts(oem plugs, etc)...check fuel injector duration, etc. It should be a simple fix, just kind of a pain to pin point

 

Well I just picked up my car from Honda dealer and they said that the Code P0171 is an O2 Sensor failure and specified that the Primary O2 Sensor is bad and needs to be replaced. They want $430.00 to replace it. OMG!

Is the primary o2 sensor the one on the exhaust manifold? If it is I can pick up an O2 sensor from autozone for $80 and replace it myself.

Thanks everyone for your help and support.

 

primary is the one before the cat... so yes. i'm replacing mine as well and was told to stay away from everything but denso or ntk (made by ngk).

 

Is Bosch OK to use? That's the one I'm getting from Autozone.

 

Are they denso or ntk?

No, bosch is awful from all the reading I've done.

 

I've had Bosch before, they worked for my Toyota 4Runner.

they at least lasted 2 years before I sold it.

 

best bet is to order off the internet, and maybe pay a lil more. autozone stuff is usually overpriced, and not the best quality (compared to what u can get on the internet for the same or a lil xtra). ive never replaced my primary o2 cencer, but my plug wires went bad and autozones didnt stay on with a tight seal. thats just my outlook on autozone parts.

id agree with mike_c, get the ntk cencer

 

Honestly i wouldn't use a aftermarket o2 sensor unless it was a denso...i've seen alot of cars run worse with the replaced o2