stacyy86

Hi everyone! I don't know much about cars, so I figured I would ask you guys.

Anyhow, I have a 98 Civic LX that keeps failing smog due to the Functionality test. It has failed it twice. My check engine light is not on. At first, the technician said to keep driving it around and to come back. I commute to work daily ~20 miles each round, and drove to visit family for Xmas break ~300 miles each round and back. The next day after visiting family, I returned for the retest. The technician ran a pre-inspection to see if my monitors would pass, but three were still not ready. I believe it was the O2, CAT, & something else that wasn't ready. The tech was kind enough to not use up my 2nd retest, but he said I needed to get it checked out since driving that much should have reset the ecu/monitor?

Should I go have it run for a pre-inspection at another place? Should I reset the codes by taking out the battery then putting it back in? Do you think I have faulty wiring or a messed up ecu?

Your input is much appreciated! Especially as I just received a fixing ticket. Thanks so much!

Hybrid96EK

I would reset the ECU and try again. I have found it best to set monitors by taking a short 10 mile trip around my neighborhood. It involves several stop and go's followed by a short trip on the highway. Sounds like you are not setting O2 and catalyst monitors. Those are usually the last ones to set.

hondacrx2

Reset it and it could take up to 250 miles but like the other guy said stops and goes are key. Certain monitors need certain peramiters to reset. If it doesn't pass because of the cat. Buy a defouler it's like 35$ way cheaper then a cat! Unless in Cali then your screwed. I do inspections in pa. P.s. You have to keep the battery out for a few to reset the monitors just a 2 sec disconnect wont rest them.

Former User

Also check whether the hood Back Up fuse is blown.

stacyy86

Where is that located and how does it look like?

By the way, would it help to mention that before going in to my second smog, in addition to driving it the weekend before a total of about 600 miles, I drove it on the highway about 20 minutes and through town about 15 minutes, and it still didn't pass. Would this mean it's taking longer than usual to reset? Thanks again!

Former User

There's a fuse box under the hood near the battery. You'll see a fuse named Back Up printed on the plastic hood fuse box cover. It's a 7.5A fuse. Check whether it is blown.

hondacrx2

Don't laugh but make sure your gas cap is tightened I have seen cars fail because of that.

stacyy86

Thanks everyone! I'm going to the smog shop to see if it passes the monitor tests tomorrow. I'll let you all know how it goes!

travbrack

Not to threadjack, but I ran my car for a few months with this fuse blown unknowingly. If the ECU is on it, doesn't that mean it shouldn't work at all?

Former User

No. The engine would still run. The Back Up fuse is for the memory of the radio, clock, and ECU. Memory of the ECU stores learned information required to make the ECU ready, which is the problem the OP is having.

chucky420

That fuse just provides a "hot at all times" power source for the ecu, mostly for memory. The ecu draws power from a "key on" source to run the engine control. The car will run without this fuse, but the ecu will lose all power when the key is turned off. The ecu won't develop a memory and the emissions equipment (EGR,EVAP,Catalyst) will show "not ready" indefinitely when the inspection is performed. I think it will also stop the ecu from going into "closed loop" and properly adjusting fuel trim. But even if it will go into "closed loop", with it's memory being erased each time the key is switched off, it will have to start all over again and won't recognize any long term trends.

Hybrid96EK

Exactly. She would notice the fact that the fuse was blown when the clock wouldn't hold the correct time.

st00lenpeace

Light it on fire, roll it down a hill, and walk away!

stacyy86

Mkayyy, this might sound dumb, but how can I tell whether or not the fuse is blown? Thanks everyone! <3

stacyy86

Oh, and I'm not sure whether or not the clock has the correct time. I don't have the stock radio/stereo which is where the time was displayed.

Former User

Test 1: Remove the 7.5A hood Back Up fuse and check whether the metal link inside the fuse is broken/melted. Make sure it looks like one of the good spare 7.5A fuses in the dash fuse box.

Test 2: This is the ultimate fuse test, but you need a test light or multimeter. Do you have one?

Winlight

pull it out and look at it.if its blown you will see where its blown most likely

stacyy86

No, I don't have one of those, but I can buy them at an automotive shop I'm guessing?

Former User

You'll get a better deal at a Harbor Freight Tool store. You could even check at Walmart. An inexpensive test light will be adequate for testing the fuse.

Start by visually inspecting the Back Up fuse. Post a picture if you are not sure whether it may be blown

stacyy86

Okay, thanks so much for your help! And everyone else! I will take a picture if I am unsure. I'll be sure to update you guys as well.

NOFX

Sometimes they will test fuses for you at parts stores such as Autozone, btw.

I work at an Autozone and I'm also female.

stacyy86

Oh, hey, thanks for the heads up! Maybe I'll ask if they can test it for me. Everyone there is always usually really nice & helpful.

sanchez6686

sanchez6686

my 97 civic is doing the same thing it wont pass smog due to the emission moniters not being ready. i inspected all the fueses and they all pass. i can moniter the moniters with my scanner and see if there ready.as soon as my 02 sensor is ready and i turn off the car and then turn it back on it defaults to not ready again. does anyone know a way to fix this problem

sanchez6686

help