110 leaded, not good
 

I accidently put 110 leaded gas in my car about 2 weeks ago. I meant to put 110 unleaded which is probably still to high of an octane, but not as bad as 110 leaded. The pump was labeled leaded by mistake after i checked with the gas station apparently. My car won't rev past about 5 thousand, once I pass that the car gives up like something is holding me back. At first I thought the ecu put me in limp mode, but I don't think it would make sense b/c my car revs to 9 thousand fine from a stand still. I'm taking it to mazda on saturday to get the fuel filter and spark plugs changed. Below about 5 thousand the car runs fine, you would never know it had a problem.
Iv'e had 2 full tanks of 93 octane in my car since the 110, and the problem has not gone away. What could this be?

Lead eats cats.

And would eat a couple hundred bucks out of your wallet if the dealer finds out.

The CAT is most likley clogged. I would not say anything to the dealer about 110 gas. Also unless you modified your car to run on 110 anything over 93 is a waste of money. Expect to make two trips after their first attempt doesn't fix it.

I'm catless. I knew it would mess with my 02 sensor and my cat. Didn't expect the gas to make much of a difference, went with a friend who has a rx-7 and just wanted to try it out. Obviously bad decision making on my part though, lol.

So you are saying that you have a midpipe?

To be honest, lead poisons catalytic converters and would not NECCESSARILY cause the cat to physically degrade. But three points of evidence lead (HA) me to that conclusion. 1) When RX8 cats colapse, you cant rev over 6krpm. 2) RX8 cats have colapsed on more than one (or two (or three...))) occasions. 3) you dosed a HUGE about of lead. For leaded gas it is the tetraethyllead that give it its anti-knock properties. Old regular was in the 80s. So if you have a midpipe I expect you screwed some sensor somewhere. Will think on this. Do you have a canscan or some other equivalent OBD reader? Look for some pegged reading. that Might get you started in the right direction.

The o2 sensor is most likely the problem. Lead will plug it a lot faster than the cat. When plugged the ECU will not get the proper input causing your problem.

I have the bb race pipe. The original o2 sensor was stripped, I simply put a bolt in the 02 bung. I have been running with no 02 sensor for quite some time now and it was running fine.

you had a cel though correct?

you mean the after car o2 sensor right?

Yeah Iv'e had the CEL light on, and it was running fine.

I Don't Think They Make Leaded Gas Anymore It's All Unleaded.it May Just Be The 110 Oct Giving You The Problem

they still make leaded gas. its just not all that widely available.

110 leaded race gas exists and is quite common.
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Sensor....
 

The Primary O2 sensor may be poisoned, you have a bung in the hole for the secondary sensor, the one that was on the cat itself.

The car will probably go into "limp mode" if the first sensor is detected "bad", sounds like your symptoms.

I agree with CarbonRX8, lots of lead will stop the catalyst activity, but not plug it up. (if you had one)

Good luck at the dealership without your cat! If you don't put it back, you may be S.O.L.

S

agreed, new primary O2 sensor and leaded gas will not plug a cat

the primary O2 sensor is located in the exhaust manifold/header and is what determine the engine fuel ratio delivery, the secondary O2 sensor in the midpipe is for emissions verification and doesn't affect how the engine runs

I do have to ask why you wanted to use 110 octane in the first place, leaded/unleaded aside? You won't any more power with it. In fact, quite the opposite.

I didn't think about the o2 sensor in the header, that might also be the problem. I didn't expect to see much of a gain in power if any, but I tried it out anyway. I accompanied a friend with an rx-7.