okay, just bought a 1999 civic ex model... the car idles great - it purrs like a kitten. transmission seems to shift fine (automatic). what its doing is it feel like it has no power when your trying to take off from a stop or even accelerate while your already rolling. the car will cruise at 60mph just fine (fastest ive had it)... at any speed if you try to mash the gas around half throttle or more it just feels like it instantly goes to have 50 horsepower. it doesnt buck or skip or anything, just no power. also barely climbs hills or grades. first off the car has 270k miles lol, but it runs great... also has a "short ram" intake with an exposed filter element. the codes im getting are:

bank 1 sensor 1 oxy sensor, catalyst inefficiency, misfire cyl 1,2, and 3, intake air temp sensor, and random cyl misfire... whoever had the car before me removed the stock muffler all together, so i put my hand over the exhaust pipe with it running and it feels like it has good exhaust pressure? most of the time when ive dealt with bad converters i can put my hand over the tailpipe and feel heat, but not very much pressure. this feels like its pumping out exhaust pressure fine. any ideas? thanks!!

 

You are in limp mode. Checking O2 sensors and your catalytic converter would be a good place to start along with a tuneup.

 

thats what scares me... someone had JUST put some spark plug wires and dizzy cap on this thing... when i went to pull each of the spark plug wires it felt hard as heck to pull them out and seemed like they were starting to pull apart... i pulled the IAT sensor out of the intake and it looks fine, not too common for them to go bad or so i thought- is there anything else that could contribute to the IAT code and maybe linking it with bank 1 oxy sensor and catalyst inefficiency? also, wouldnt the exhaust flow feel stopped up or like it has no exhaust pressure coming out of the tailpipe if the converter were stopped up? and i thought bank 1 sensor 1 one was the upper oxy sensor that accounts for the fuel mixture and has nothing to do with detecting the converter efficiency... isnt that what the downward oxy is for? i guess i could at least throw a oxy sensor and IAT sensor on the car tomarrow and disconnect the cat and see what happens...

 

Plugged cat. I would start with the cat and o2 sensor as mentioned.

 

cool, ill get on it tomarrow and see what i can find. just bought it tonight so just wanted to get some input before really looking at it tomarrow. lets hope its cheap and simple and not somebody elses nightmare! thanks

 

Does the exhaust smell like eggs at all? If you shake the cat do you hear broken pieces inside?

 

dang... i forgot isnt there a huge converter made into the exhaust manifold on this car? or is there just the one small one inline with the exhaust pipe?

-pityo... i did not notice the egg smell when driving it, it does have a rattle (definately not upper engine vavle or rocker rattle) coming from somewhere under the car when you revv it almost like a "pinging" or "thin metal" sound although like i said i just bought it and got it home (and its been raining here all day so the ground is wet) and havent crawled up under it yet.

 

Should be a pre and post O2 sensors with the cat in the middle of the vehicle

 

if i remove the cat altogether is it going to pull a code for not having one? guy locally selling whole exhaust setup from headers, back to muffler and it has a test pipe instead of cat... cheaper than actually buying a converter for the car is why im asking

 

Lessee. Removing the emissions equipment from a car when the ECU is looking for it? What do you think will happen?

 

You first need to clear the codes and see what comes back. Then start from there.

 

I believe you can if you use a 10 mega ohm resistor inline (O2 sensor signal line, not sure which wires) - in place of the post O2 sensor. Someone may be able to chime in on this and which wires...

 

You can always trick it...

 

Yeah but we're getting ahead of ourselves.

 

I had a car years ago where the cat plugged and it had no *****. You would get ready to get on the freeway and it dragged *** same with small hills. Replaced the cat and O2 sensors and all was well...

Maybe find someone with a spare good Cat and see if it changes things before buying one?

 

True. Just throwing out options...

... I would clear the codes as mentioned and start from there.

 

well got the cat pulled away and tried to look in there with a flashlight... still see the honeycomb in there, anyway to tell if its clogged? doesnt look like theres any buildup in there... im going to hang it up with a clotheshanger (dont hate, lol) and drive it around running open manifold when here in a few hours when i get the chance and see how she does... also have the battery disconnected to drain the codes.

 

well i replaced the upstream oxy sensor and cleared the codes and it seems to be doing fine now... it was shifting weird before too, but seems to be alot better. i only drove it around the block (pressed for time) so hopefully it will stay that way... you guys think that could have also for some reason tripped the code for the misfires and the IAT sensor? looks like the IAT sensor in the car was fairly new... it does have a cheapy "short ram" intake... would this be the cause? anyway, no lights on for now, but i know hondas take a few drive cycles to re trip the light so we'll see what happens