soooooooooo
i just changed the exhaust on my civic - apexi ws 2 and put on a new catalytic converter-
(not me, my boyfriend did it- im stupd when it comes to cars)
the check engine light is on, we had it checked- something about emissions or something-
but now when i drive it the car jerks and the speedometer needle jumps btw like 20 and 60 even tho im going like 10mph...
this makes nooooooo sense to me, i have no idea whats happening with it- if you have any ideas at all please please help me!! (the only other things that were done was the rims were changed today, but i dont think that would have anything to do wth it, and the battery was disconnected then reconnected)

 

What year? Did you hook up the secondary O2 sensor?

 

its a 98 ex coupe... sorry for not mentioning it...
whats a secondary o2 sensor?? i guess not knowing what it is means that it wasnt hooked up- do u think that could be causing all the problems? even the speedometer needle thing?

 

no having the o2 sensor shudent be having that big of a effect on the car.. just just be running either a little lean or a little rich.. wouldnt make a big diff like that. im kinda confused on you problem tho... no shure what u mean by needle just jumps up

 

well 1. the code it yhrew was P0420 Catalyst System Efficiency Below Threshold and 2. what i mean by the needle jumping was that when i accelerated, the needle would fly up to near 100 and then quickly back down to around 20 then wobble between the two- does that explain it better?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TomatoRed &raquo;</TD></TR><TR><TD CLASS="quote">well 1. the code it yhrew was P0420 Catalyst System Efficiency Below Threshold and 2. what i mean by the needle jumping was that when i accelerated, the needle would fly up to near 100 and then quickly back down to around 20 then wobble between the two- does that explain it better?</TD></TR></TABLE>

You said the car jerks when it does this?

Could be a slipping clutch...

Is there any time specifically when this happens? When you get on it harder? All the time? Engine hot? Cold?

 

you should problably just have a honest mechanic look over the job your boy did for you, he could have disconnected something and forgot to put it back, thats very odd though. Why did you put a new cat on your 99 honda????

 

its automatc... no clutch
but it does jerk and the needle jumps up and down

 

P0420 is due to not having the secondary O2 connected correctly or simply not having a truely working cat. Was it a "high flow" from ebay? They set this code a lot.

the speedo... sounds like the plug is loose on the trans or the ground is messed up.

Have your BF double check all the connections around the exhaust. Make sure ther are no dangling wires and all plugs are tightly connected.

BTW, stupid about cars is not the right term. You're a noob who's obviously not afraid to learn. Or at least ask questions.

 

i put a new cat on cuz when i was changing out the exhaust (the old one was rusted and had a huge hole in it), we coldnt get the old cat off (we tried for like 3hrs, blow torch and everything).. so i had to get a new one

 

how much was it? I would get it checked out by someone. If you have this code that means your emmisions are 150% above regulation.

 

the cat is an obx hi flow cat- i did buy it off ebay (it was lke $150) -was that a bad move??

im gonna have him check the wiring tomorrow- cuz its the only thing i could think of also that might throw that off

 

Yea that is a cheap cat. Some cat are close to 500 at dealers.

 

is there a different one i should have gotten that wouldnt have made my car all weird??

 

?? cuz if there is, ill change it- i dont know what else to do to fix it

 

I have a 95 ex and it only has one o2 sensor, but yours has 2 (b/c it is a newer model). one of the sensors is located on the cat I THINK. the thing with the needle jumping sounds like a speed sensor to me b/c the same thing happened to me when i replaced my clutch, i forgot to plug up the speed sensor and the needle jumped all over on the speedo, but my car did not jerk so i don't know. it also happened on my moms suv and it turned out to be a speed sensor as well (her car did jerk when this happened, but it is an auto).

as for the cat, id say get an oem one or go to a performance shop and get a good high flow cat.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TomatoRed &raquo;</TD></TR><TR><TD CLASS="quote">its automatc... no clutch
but it does jerk and the needle jumps up and down</TD></TR></TABLE>

oh and just so you know, an automatic does have a clutch. actually it has a clutch for each individual gear so it has more than one clutch

 

oops- i told u i was stupid!
haha
sooooo if its the speed sensor- what can i do to fix it??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99d16 &raquo;</TD></TR><TR><TD CLASS="quote">take it to honda </TD></TR></TABLE>
k no, don't take it to honda, their gonna milk you.

there isn't an o2 sensor in the cat, theres one before and after if anything.

the speedometer jumping up and down might be an eletrical problem..ur bf might have hit something while putting on the exhaust. i.e. speed sensor, which would be on your transmission, which could also be why your car jerks.

lastly, ur not stupid ur afraid to learn like Relic1 said. maybe not afraid..but u kno.

 

i'm definitely gonna have him check the fuses and speed sensor- but i have a problem- the car came w/o a manual, and the inside of the fuse panel thinggy doesnt have the layout of which fuse is which. is there any way i can get a diagram of it somewhere online or something??

ps- thanks for all the help and not thinking im retarded! lol

 

Your old cat had a hole in it or just the exhaust? If the old cat was fine why not just throw it back on? Also a little known fact, Honda has something like an 8yr 80k mile warranty on their cats and will replace them free of charge. Got mine for free

 

the cat didnt have a hole, the exhaust did... the old exhaust was so stuck to the old exhaust (we couldnt get it off- even with blowtorching and everything) that i had no choice but to order a new one... i didnt know that warranty thing, but i bought the car used just a few months ago and it had about 86,000 miles, so im not sure if it would've applied

 

Oh so basically the old cat is stuck on the old exhaust. If i were you, Id bring that entire thing to a muffler shop to have them remove the bolts with some proper tools. It would certainly beat dishing out hundreds on another cat.

 

haha thanks but its a lil too late for that- the old one's gone and i already have the new one

 

I had a light in my 93 civic but i forgot to the plug the o2 sensor back in.
This is the catalyic converter i have.. was like 25 bucks. im not sure what the 150 or 500 ones do. unless its not a cat and i got ripped? lol
http://cgi.ebay.com/ebaymotors...sting

 

i got this one...

http://cgi.ebay.com/ebaymotors...wItem