passed smog, but still loping.

mxhooptie · Post by **mxhooptie** » July 11th, 2007, 11:31 am

at cold starts in the morning, it idles fine. as it warms up, the loping begins and the car shakes.

the car accelerates smoothly. once it's in motion, there seem to be no issues.
except for the gas smell from time to time.

but once it comes to a stop, the loping returns. the muffler sputters too.

sometimes, the car does NOT lope when at a stop. but it lopes again once i put electrical load on the car.
in fact, i notice the rpm drop a little every time i turn on the head lights or activate the brake lights.

mxhooptie · Post by **mxhooptie** » July 19th, 2007, 12:16 pm

it seems you are all stumped about the loping.

well, forget it. but now i need help with emissions. not sure if it's related to the loping, but i need to pass in ten days.

my car is not burning fuel all the way it seems.

i've changed the plugs. wires and cap are relatively new. i've inspected and cleaned the rotor. i found no vacuum leaks. i've adjusted the TPS and idle.

the spark plug tip has white stuff on it. what exactly does that mean? i've read different things.

Tunes67 · Post by **Tunes67** » July 19th, 2007, 12:23 pm

White powdery stuff is an indicator of oil burning in that cylinder. My bet on the loping issue and your emissions issue is a plugged catalytic converter. There are ways to test it.. but you likely dont have a laser or infrared thermometer on hand to use. You could maybe find a mechanic that has one.. Cats are fairly easy to test without doing much.. point the infrared thermometer at the pipe BEFORE the cat and get a temp reading. Record the reading. Then point the thermometer at the pipe AFTER the cat and record the reading. Believe it or not.. the Temp reading AFTER the cat should be about 100 degrees higher (give or take 20 degrees) than the temp reading BEFORE the cat. If the catalytic converter is funtioning as it should.

Tunes67

mxhooptie · Post by **mxhooptie** » July 19th, 2007, 7:07 pm

hey Tune67,

you told another guy about a much simpler cat test:

Tunes67 wrote:If you have a rotten egg smell from the cat.. it is plugged and will need to be replaced. Put your hand over the end of the exaust pipe (only when cold.. dont burn yourself) and have someone start the engine.. you shouldnt be able to keep your hand on the pipe.. but if there is a blockage in the cat.. the pressure coming out the back of the pipe will be weak.

did you mean just literally putting my hand over the pipe, or pressing my palm over it with a little force? btw, i don't smell rotten eggs. i do smell gas fumes.

if my cat is indeed blocked, will this work as a replacement?

http://cgi.ebay.com/ebaymotors/93-97-MA ... dZViewItem

Tunes67 · Post by **Tunes67** » July 19th, 2007, 8:11 pm

That is a fairly simplistic test.. and not always a conclusive one.. the temp check is usually more accurate. But, yes, if your exaust flow is so weak you can keep your hand over the end of your exaust pipe while the engine is running (this will eventually burn your hand) there is likely a blockage in the catalytic converter.

Now as for that ebay link. I dont think thats a actual catalytic converter. I think its a bolt in test pipe that will go in place of the cat. For racing purposes.. it can free up exaust restrictions/ lessoning backpressure. But for your application.. it wouldnt do anything to help burn off your excessive hydro carbons. Which is what you need to pass emissions. I'd recommend going to a local exaust shop and getting a new cat from them. If you dont want to pay them to install it, you can always install it yourself. I think that will be a more certain method of getting the part you need.

Tunes67

SuperK · Post by **SuperK** » July 20th, 2007, 6:19 am

Like I said earlier, the cheapest OBD-II EPA Certified cat I know of is one from Magnaflow.

That's what I'm running right now and loving it. Get one for under 70.

mxhooptie · Post by **mxhooptie** » July 20th, 2007, 1:51 pm

hey SuperK,

your point was taken. its just that i was betting/hoping it wasn't the cat.

so, a '95 RS in the US is OBD-II? i thought it was OBD-I
my engine isn't listed here under pre-96 OBD-II cars.

Tunes67 · Post by **Tunes67** » July 20th, 2007, 1:58 pm

Most 95 MX-3's ARENT OBDII There are a few.. but those are phase in or test models so to speak. OBDII wasnt standard in the MX-3 till 96.

Tunes67

SuperK · Post by **SuperK** » July 20th, 2007, 7:51 pm

We're OBD.... 1.5
or OBD 1.666 if you please. Depends on how you feel about your car.

We're OBD 1, but it seems that our 95's are slightly different.
A bit compatible with OBD II standards, I'm not sure how it works. But apparently we get better luck with swapping new gen BP's than the 93's. Or something. I dunno. Word.

mxhooptie · Post by **mxhooptie** » July 22nd, 2007, 1:08 pm

ok, i'll replace the cat. hope this fixes both my problems.

i'm getting the Magnaflow listed here

mxhooptie · Post by **mxhooptie** » July 26th, 2007, 12:30 am

passed finally. but my car still lopes. which means it's still misfiring. which means it's not combusting thoroughly. which means this new cat won't last until my next e-test.