Hi...I'm new to the site...My GF has a 2000 Protege ES.

Her check engine light was on a few months back and we had it read...came up with 3 codes, 1 small exhaust leak, 1 larger leak, and a 3rd code that i cant remember...

her large leak was cause her airbox had a broken clip, i fixed it and we had the light reset...

it came back on a day later...we just had it read and the mechanic said it was Code P1114 or P114...Warm Up Improper? he advised that she let the engine run 5-10 minutes each time before driving...

today, she was in a rush and only let it run for about 1-2 minutes...outside temp was about 70+, car had just made a 20 mile commute with no light...she got out of class and left, thats when it came back on...

Mechanic thinks it has something to do with the Remote Starter that i put in her car, but I HIGHLY HIGHLY doubt it as I have installed these things to many cars and have not had any issues...

any suggestions from the experts here???

thanks...
Mario

 

Hi Mario.
Do you have any other information on the code numbers? Very critical that we know the exact code that has been set as there are a little over 100 different ones that could be set for the 2000 Protege. I assume that she has the 2.0l engine as it is an ES but double check. There are not any codes for exhaust leaks but there are several for EVAP system large and small leaks. There is also no code #'s P1114 or P114. All codes for engine/trans should start with letter P and then followed by four numbers. There is a P1141 that indicates a possible fault in the downstream O2 sensor heater. P0420 or P0421 would point to a front warm-up catalytic converter efficiency below limit. If you could have the code number rechecked at an Autozone and post back up could probably be of much better assistance in what it could mean

 

Check Engine Code is p0421...

have read that this could either be the o2 sensor or the cat converter...

any ideas of how to check each? also if it is the cat, can i just get a universal cat that fits in there to replace it?

thanks...
Mario

 

Only very rarely would a faulty rear O2 sensor cause a P0421 Cat Efficiency. If the rear O2 was not operating correctly it would more likely set a P0138 or P0140. A non OE converter could be used but would need to be fairly model specific as the bolt pattern of inlet and outlet as well as length would need to match OE part. Is not like a main CAT that you can cut out and weld a new one in. This one bolts right onto the outlet of the exhaust manifold.

 

My check engine light came on night before last. The error code is P0421 and msg stated Catalyst efficiency below standard. Can you help direct me to what I need to do?

 

just for info. i found this on the tube

 

I also have a 2000 Protege ES (1.8) with P0421. I bought it about 6 months ago with 140,000 on it.

After changing the spark plugs, pcv valve, air filter and intake hose (was taped and cracked) and cleaning the mass air flow, a lot of my idle and throttle issues were fixed and all of the codes went away for a while... P0421 came back... In the beginning it was intermittent.. The car does a lot of city driving so I took advice from others to take it for an extended drive on the highway, I guess, in theory, to heat up the cat. This seemed to work sometimes. But just when I thought it was gone for good, the dreaded code comes back.

Now I'm not a mechanic but my research has led me to believe there are two options (at least for me) at this point, which are:

A. Attempt to clean the cat either directly by removing or by fuel additive (controversial?) Scotty Kilmer has a video on youtube where he recommends using lacquer thinner in the gas tank to clear catalytic efficiency codes. I have not tried this yet as I'm concerned about using such a powerful solvent in my fuel system and can't back up the claims with any other reliable sources.

or

B. Install non-fouler between the appropriate O2 sensor and exhaust line as shown above.

I'm personally not considering replacing the cat as an option due to cost and stories I've heard of the code still coming back. I'm not sure if this only the case with aftermarket cats, or what.

Will try the non-fouler as a last resort. Have less than 6 months before inspection.

If anyone has any advice would be appreciated.

 

I have tried the lacquer thinner at half strength. Went for a 45 minute drive on highway right after putting it in. Mind you i didn't have code, just wanted a good cleaning. It worked. Car runs great.
Tanprotege has also done this and he actually had a code. It did wonders for him.
remember: lacquer thinner NOT paint thinner


Installing a fouler will only mask problem if it is showing up as partly clogged. However, Scotty Kilmer does say the light may come on as early as 5% plugged!?

 

That's reassuring. I was particularly concerned because some folks were saying something about it eating away at the rubber in the fuel system. I'm sure the dilution is an important factor.

I couldn't tell you the difference between paint and lacquer thinner but I will be sure to make the distinction if I ever attempt to do this myself..!

 

Both are clearly marked and available in 1 quart/litre containers.
Get the lacquer thinner, NOT the paint thinner.