armascivic

Hey everyone well this is my first post on this website and i must say its really helpful. There is so much info on this site im having a hard time comprehending everything yet im excited about just owning a Civic i love my car and im equally impressed with everyone's expertise, but now just as this is my first post and it is my first ever car problem and any advice would be greatly appreciated.

So I own a Honda Civic 2000 LX 4dr and bought it about 2 years ago with 167k miles on it but ran pretty smooth. A year after owning my Civic i decided to put some Chevron Fuel Injector Cleaner Additive from Pepboys into the gas tank as directed, then filled up the tank with Chevron gas. The next day after i filled my tank, my engine started rattling and knocking pretty bad to the point where i pulled over because of how afraid i was.The engine rattling was VERY noticeable and embarrassing when stopped at red lights. The CEL light also came on and would blink all the time i was driving. Also, the emissions strongly smelled of unused gasoline.

This problem did not go away even after burning through all the Chevron gas mixed with fuel injector cleaner additive. I then filled the tank with regular 76 gasoline and still the engine rattling reduced about 10% but was still significant. The CEL light changed from blinking to stable on while driving.

After using up all the 76 gas I took the car to Pepboys to get it repaired but they really didn't know what was wrong with the car so they gave it a Platinum Maintenance Tuneup Package about $200 which includes new spark plugs, distributor rotor and cap, and BWD Automotive Custom fit wires, basically new parts to fix what the mechanic thought was a weak spark not igniting the fuel.

After the repair, the CEL went away and the car felt great like new almost. Acceleration and power from the engine instantly returned. But sure enough a week later, the engine started losing power and acceleration until eventually........the CEL came back on -__-

Around that time i discovered this site and found how to get the CEL light to flash a code which to this day flashes a 67 which is a bad Catalytic Converter. I went to Autozone and Pepboys to try to get someone to run a more detailed diagnostics with the OBD2 scan tool? but they refuse do to it for free anymore. So at Pepboys a mechanic explained to me what i already learned from this site which is a bad Cat also signifies bad oxygen sensors both secondary and primary.

So my question is could someone confirm that this is indeed the problem with my engine and what problems would i need to fix. I have been working at Six Flags saving up about $1000 all summer so far to get this fixed and the mechanic estimated that new sensors and a new Cat from a muffler shop would be around $900-$1,100. I would spend that much to fix this but ONLY if the problem is completely solved. Like i don't want to spend another several hundred dollars just to have the real source of the problem screw up a new Cat. Also, is there anything else i should fix or replace such as the spark plugs(again) and distributor cap-rotor so i can get that performance back i had from my engine after the $200 tune up at Pepboys.

I would be very willing to buy the parts myself like whatever I need and replace anything i can myself and whatever i can't replace i could get my friend's dad who is a mechanic to also fix it for me. Again i just need the parts and a good place or website to buy them from. I really don't want to go with cheaply made parts. Im looking for Bosch oxygen sensors(the right ones) and idk which Cat to get yet like which make and model is right for my Civic.

Thank you in advance to all who read this novel i posted as well to any help again it is greatly appreciated. Any pictures and links to parts i need or that are recommended would also be appreciated. Thanks again everyone

Former User

When the CEL blinks while driving, it means that engine misfiring is so severely that the catalytic converter (cat) is at high risk of being damaged. When this happens, you should immediately stop driving the car so as to avoid the high cost of replacing the cat.

When this happened and you brought the car to Pep Boys, the mechanic should have pulled the CEL codes at that time. At least one of the codes was surely for random misfires, but were there others? That might be informative to know.

The fact that plugs, wires, cap, and rotor have not fixed the problem suggests that (1) they were not the problem, (2) the ones PEP Boys installed are not good quality, or (3) the cat has now melted is clogged.

Now the bad news. Code 67 is not thrown by bad O2 sensors. In your case, this code has a 99% chance of being caused by a melted/destroyed cat. Unfortunately, it's expensive to replace, especially if you buy a new OEM one. The good news is that the OEM one is relatively easy to install.

If your current problem, besides code 67, is power loss, this may be caused by a clogged cat. After the cat substrate melts, it can block exhaust flow and thereby reduce power. However, before you replace the cat, make sure that the engine is no longer misfiring. Otherwise, you will very soon be buying a second expensive cat.

ChevelleSSLS6

I run napa parts, or at least name brand parts from the price leaders (moog chassis and steering parts from advance auto parts, for example). Napa is a little more $$, but I never had a crappy part from them. Sure the cheap brakes, like anywhere, will make dust, so I buy raybestos, wagner, oem, or a quality performance brand for brakes.

If you go to autozone or one of the other stores like that, get an actual name brand part. The napa branded stuff usually has who it's made by on the box, and that company is normally a factory OEM supplier to one of the big auto companies.

armascivic

Yeah I knew the CEL blinking was really bad thats why i pulled over and turned off the engine and checked it out but unfortunately i did drive on it hoping that it would go away which was dumb so now i have a completely bad Cat because of it.

When i went to PepBoys, i had no knowledge of CEL or OBD2 codes so I just told the mechanic what was going on with my car and he checked it out and told me what he believed was wrong with it which he thought was misfires caused by a weak spark. I still have the receipts from the tune-up he did to attempt to fix this problem but the receipts does not have any codes on it. I know now that the tune up did temporarily fix the symptoms but not the real problem which is the bad Cat. I can go back and pay him to pull the codes out from my car again and give them to me this time if you suggest it.

I believe your right about the distributor cap/rotor and plugs to not be the actual problem and also that my Cat is clogged/melted now so i am going to fix the Cat this time.
I also know that a CEL code 67 means bad Cat but after some searching on this site i also learned that a bad Cat usually also signifies bad oxygen sensors as well. I didnt know that a bad Cat takes away power from the engine but thank you for telling me that because i was wondering why i was losing power.
My greatest fear is replacing the very expensive Cat only to have the faulty oxygen sensors screw up my new Cat which will eventually cause me to have to purchase another new Cat. So my thoughts are just to replace the Cat and oxygen sensors at the same time. Is that a good idea?
If so im just going to have Pepboys replace my oxygen sensors while i buy a new Cat that is legal in California and replace it myself since you say its easier to install myself.

armascivic

Is Napa a brand for Catalytic Converters?
Yes i think i will just get one from Autozone hopefully a name brand OEM one, hopefully under $300

Former User

The original problem was engine misfiring, which subsequently killed the cat. The original misfiring quite possibly WAS due to bad plugs, wires, cap, and/or rotor.

It's too late, don't bother. He most likely reset the ECU and cleared the original codes.

You may have read this^ somewhere but the information is incorrect for your Civic (if the only code currently thrown is 67).

Based on the information you have provided, there is no reason to believe that either O2 sensor is faulty. You need a new cat. Again, just make sure that the engine is no longer misfiring. Otherwise, be prepared to replace the cat again before you know it.

With help from your mechanic buddy, you would have no problem replacing the OEM header/cat for your car.

armascivic

Hmm your right because the dumb Chevron fuel injector additive was causing the misfires somehow which also caused the Cat to go bad because i drove with the bad gas.
So does that mean that my current spark plugs as well as the distributor rotor and cap are good and don't need replacing??

Well i know that but i mean would having pull the OBD2 codes tomorrow would there be any chance of him finding a different code signifying anything other than a bad Cat?

Oh okay well does that mean since the information was wrong that my oxygen sensors are bad or good? Should i replace those at all or wait til after i replace the Cat to see if they are good or not? I reaaalllly dont want to damage the new Cat im going to install. Because they are way too expensive.

How do I check if my engine is misfiring? I dont really know what it feels like when an engine misfires. I mean i drive my mom's Honda Pilot and it feels great. The gas pedal is very responsive and the engine runs smoothly compared to my Honda Civic which runs not so smooth and the the gas pedal is not very responsive. And by gas pedal i mean when u push down on it and how the engine reacts to each push. Also, i do kind of feel as if my Civic is running and occasionally it will skip or stutter which im guessing might be a misfire. I will pay more attention to this now because like i said i want to avoid buying two new Cats. Thank you for the help and the picture RonJ@HT i really appreciate it. Its really detailed i didnt even know where the Cat was until now.

Former User

You should inspect all ignition system components and check the spark plug gap. If the PEP Boys mechanic installed anything other than NGK ZFR5F-11 spark plugs, remove them and install the latter.

You don't need a code reader to pull the codes. Just jump the service connector. If only code 67 is retrieved, then that's all that's thrown.

I'll reiterate. There's NO REASON to believe that your O2 sensors are bad. Therefore, leave them alone. Period.

Just make sure the ignition system (plugs, wires, cap, rotor, ignition timing, coil, and ICM) is in excellent condition. Then watch your CEL and pull codes if it turns on. Create a thread if anything is not acting correctly.

armascivic

Ohhhh ok got it well then i will just inspect all the ignition system components and spark plug gap before and after i install the new Cat. As you said there should be nothing wrong or else i would have had the CEL throwing a code for bad oxygen sensors which i dont thankfully. Thank you so much for the help i think in the end i hope to save about $700 in labor costs because now i know i only need to replace the Catalytic Converter and check all the ignition system components. Hopefully everything goes well and i can use the savings to tune up my car just gotta shop for a new Cat now...

HondaPartsHero

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