jmars808

Hello,

I have a 2002 Civic EX Manual Trans with exactly 145,000K miles.

On a 200 mile trip I was going around 80 mph just under 4,000K rpm (which seems high) and noticed a kind of faint popcorn sound coming from the front of car. drove slower and it went away drove back up to 80 and it came back. Pulled over it needed about a quart of oil. Sound went away and drove it slower.

On the return trip after leaving a rest area the CEL light came on. I had the guy at Pepboy's test it and it pulled code P0420. HE said I needed a new Cat.

SO After purchasing the cat online and jacking up the car getting ready to change the cat I notice I don't have one! The previous owner had someone weld a straight pipe where the cat would be and it does have the O2 sensor there and everything. Now I have had this car for 3 years with no problems. I don't see or smell and leaking exhaust and there are no visual leaks.

Now I am at a loss as to what to do ... My car hasn't made any sounds since then and the CEL has not come on since he turned it off. Every now and then I will get a slight stumble if the car has been sitting awhile and I take off from a light when I reach 4th gear. But that's about it.

Any ideas? Should I swap out the new cat and pipe I bought? Should I leave the old pipe with no cat? Would it be the O2 Sensors??

Thank you,
Jeff

mikey1

the cat is part of the header, do you have an aftermarket header?

some pics might help

BlueEM2

iTrader: (1)

The cat is not part of the header on an EX. I don't think it's possible the cat is not there unless someone before you had trouble with it and just welded a straight pipe on. Pictures here would help for sure as mikey says.

ezone

Could have O2 fooler to keep the cat code out. Either the no-foul adapter trick or electronics.

It would almost have to have something to keep the code off, because with no cat the code sets in 2 trip cycles.

BlueEM2

iTrader: (1)

^ ezone if he had no cat wouldn't the code be on all the time if there was no fouler? Maybe there is one already there it just needs to be adjusted.

ezone

It can be masked electronically too.

SOMETHING had to hide the fact it is missing the cat, or else the CEL would have been on ever since the cat went missing.


How are you gonna "adjust" a no-fouler?


Maybe he ran it hard enough and long enough that the no-fouler trick was ineffective under that particular condition? (I'm just guessing here.)

OP: Does it have no-foul adapters installed on the rear O2 sensor?

BlueEM2

iTrader: (1)

I thought it was adjustable, as in how far away it is from the exhaust, or even the bore size(new fouler) so that it reads even less exhaust but I'm not totally sure I've never actually installed one

BlueEM2

iTrader: (1)

Might let me link it, I guess you just add more of them lol http://www.355nation.net/forum/how-p...ight-pics.html

ezone

The idea is to get it away from the direct exhaust stream to sort of "numb" it to the rapid variations in the oxygen content as the exhaust flows past the tip of the sensor.

A (more or less) steady O2 sensor reading is seen when the cat is good, that is what a fooler is trying to simulate.

BlueEM2

iTrader: (1)

Yea he might need to add another fouler so it reads less exhaust in turn showing less emission which will mean the intermittent C/E light will go away.

ezone

Or just go ahead and install the cat he already purchased.

jmars808

Hi Guys,
Sorry for the delay but here is the pic. As you can see there is no cat. Just a pipe welded where the cat would be. It also has a bung that has the O2 sensor inserted where the straight pipe was welded on.
If its a code eliminator, I have no clue.

I have had the car for 3 years. Never a code till this one time 2 months ago. The guy at Pepboy's turned off the code and I think it came back on like later then went off.

The code is off now and has been off since that incident 2 months ago. I don't do much highway driving or drive it that hard so not sure if that is why the CEL has not come back on.

Now I have the new cat with pipe, new bolts, and new gaskets. I am wondering if I should just leave the car the way it is since I haven't had a problem in 2 months since the incident. This way I can return everything and get my $300 back.

Or do you think I will have problems with this set up and should change it out? The welds look a bit rusty but I don't see any leaks or smell any either.

Thoughts?

jmars808

I like that thought. That sounds like prob what happened. I guess that the thing stuck in the pipe is not an O2 sensor but a trick sensor. My girl was driving it at around 80-85MPH on the high way for about an hour when it happened.

Also, DO you guys think that 4,000 RPM in 5th gear is high for around 80MPH?? My girl has the exact same car but an automatic and her RPM gauge is much lower at that speed. I know it may be the gearing ratio but that still seems high...

jmars808

It does look like it may have one of those things that the O2 sensor is screwed into that is welded into the pipe...Maybe you can see by the pic. But it doesn't have two like your example.

ezone

Dude, your pics are 403. We can't see them.



Sorry, Forbidden.

You don't have permission to access this URL on this server.

BlueEM2

iTrader: (1)

Well you have two options. One is screw another defouler onto the one you currently have and continue to cause emissions as you drive, or hire a shop to weld the new cat on for you. I recommend what ezone said to get the new cat on. It's never good to pollute. Your basically doing what the previous owner was too cheap to do and that's replace the cat. I can't see your pictures either just assuming you have a de fouler on there.

jmars808

Let's try this again...




Hopefully using Photobucket will work for the images.

I would like to be able to return the parts I bought and get my $300 back if keeping the car the way it is and it won't in any way hurt the car or engine.

The only reason I bought the new cat is I thought the one there was bad. I am concerned that the code could have been triggered by something else like a bad O2 sensor or something else. Thus replacing the pipe with the new cat wouldn't solve anything and $300 down the tubes!

I did see your recommendations and maybe just buying an extra CEL eliminator and screwing it in between the one that's welded to the pipe between the O2 sensor should solve the issue?

The CEL hasn't come on in 2 months but, I don't do a lot of highway driving though. Car runs pretty much fine. One time a month a go after getting off the highway in a rainstorm I noticed the exhaust got really deep for like a few seconds, deep like a mustang with no muffler. lol But went away and never came back..

BlueEM2

iTrader: (1)

Add a second non fouler, or ignore the check engine light.

jmars808

Ok. Thanks. The CEL was only on for that one day 2 months ago. I turned it off and it really hasn't been on since. I guess if it comes on I'll just add a second non fouler. Thanks! As long as it won't harm the engine with this set up I'm good!

lazlong

Word of caution: These are commuter cars not road trip cars. They tend to blow headgaskets when you run them at 4000 rpm or more for extended periods of time.

ezone

Wait, what?
What's the difference? Uncomfortable on a road trip does not exclude it from being a road trip car.


You meant 'not a race car'?


The good ones will take it, the bad ones won't.

BlueEM2

iTrader: (1)

4000 rpms is fine as long as you make sure the coolant system is in good shape. Most head gaskets fail because something else causes overheating. In my case it was the thermostat leaking and me being a dumbass and not checking my coolant levels.

jmars808

Hmm...So basically I can't go anywhere far from home and drive 80MPH or above?? I usually don't drive that fast or that far but the Speed limit here is 70 mph and we have some 3-4 hours drives.

I properly maintain the vehicle with top end products. Car doesn't run hot ever..knock on wood.

ezone

I'll alert the media.

jmars808

LOL

xRiCeBoYx

iTrader: (22)

Well, I guess that explains why I had to replace my car's head gasket after 130,000 miles; those cross country and up/down both east and west coast road trips, as well as those many Vegas->NorCal trips I've taken.

Oh, wait. It could also be the fact that I had a turbo with a shitty tune for about a year.

ezone

Or it was the simple fact that you have a 7th gen Civic and it was time for it to go.


Naaaaaah, too logical. Not enough drama.