2001 Carolla With A Check Engine Light - Toyota Corolla, Chevy Prizm (1998-2008)

Guest Mikeyworks

Greetings,

I am posting for a friend. He as an '01 Carolla S with the 16V VVT-i engine (I think) and it's showing signs of severely decreased performance. It has about 66K miles on it, but other than that, it's in great shape.

Symptoms:

1) While running, but cold engine, it hesitates to an almost stall before the engine engages and you can drive away

2) Check engine light that comes right back even after disconnecting the neg (-) terminal on the battery

I checked the O2 sensor and it was a bit coked. I cleaned off the surface and used some electrical parts cleaner to clean the contacts/sensor in it.

I didn't seen any loose vacuum hoses or anything under the hood that would have given any clues.

I am thinking of limping it over to Autozone to have them get the trouble (CEL/MIL) codes off of it for me so we can see what's going on.

If it's the O2 sensor, Autozone lists one for about $100+, but is there a generic one I can use and just splice the connectors?

Thanks,

Mikey

It could be the O2 sensor - only after pulling the codes, will there be enough info to make a diagnosis.

You can't really clean an O2 sensor - all will appear coked over during normal operation. If fact you could have killed the sensor with the contact cleaner.

More likely - there is an issue with the MAF and IAT sensor in the end of the airbox. The MAF sensor can get quicly contaminated with oil, varnish, etc. - here you can use a good solvent (contact cleaner, throttle body cleaner, etc.) to clean the thin wire contacts. Just becareful and do not touch the contacts - there are very thin and can be damaged. They are located inside the main tube body of the sensor, close to the base. There is also an IAT sensor on the side that can get pretty dirty. You can clean it up the same way.

If the CEL comes back as a dead or dying O2 sensor - best to replace it with a Denso unit. There are Bosch universals that are much cheaper - but they tend to cause problems pretty quickly with these engines (their response characterists and impedance are too different than the OEM ones). Splicing them in is just asking for problem down the road - just get a Denso unit from an online retailer (for about the same price as a universal one if you shop around) and save your friend the headaches.

Good Luck.

so many people including me have had this problem with 01's around the same mileage so Im assuming the problem is a dirty maf. cleaning has helped most people and sometimes it takes several cleanings before it starts working properly but for me that didnt work and I had to buy a new maf. cheapest I found online was $128 shipped from partznet.com but you probably wont have to buy a new one. keep us updated.

ps: mikeyworks is a reference to occ? if so then what does mikey really do...has anyone ever figured that out yet? default_biggrin

Guest Mikeyworks

I will try to go and get the codes read at Autozone tonight...

I also will start shopping around for parts. Are there any good online places that you know about that you would recommend (other than the one listed above) as I am new to the Corollas and usually have my head under the hood of VWs.

Thanks for the help. I will see what I can find out.

Mikey

p.s. Mikeyworks is my company...Mikey makes it work...hence Mikeyworks.

Guest Mikeyworks

We went to Autozone and ran the codes.

We got the following:

P0171 - Bank 1 too lean

The "Tech" said it was likely the front O2 sensor...any thoughts?

Mikey

That code generally refers to when the O2 sensor reads a lean condition - not that the sensor is bad.

Chances are it is a dirty or damaged MAF sensor, a vacuum leak somewhere, or a leaking intake system.

Guest Mikeyworks

After getting home and posting last night I also did some additional digging.

I found that the P0171 code is rather common on these cars and does usually relate to a dirty or bad MAF. I will pull the MAF and see if I can clean it (very gently). If it's like the MAF on my Jetta it can't be cleaned, but hopefully it's different and ideally the two wire design vs. the electronic band design.

I'll try to post after I have cleaned it and hopefully fixed it.

Again, thanks for all the help thus far.

Mike

Hey Mikey,

Funny seeing you here. default_biggrin I guess we can't get enough of these car forums.

astonishedboy at TDIclub

Hello Mikeyworks,

My wife has a 2001 Chevrolet Prizm (same car as the Corolla),

she has been getting the 'Check engine' light on her dash, at first, I pulled the fuse, that worked for while but the 'Check engine' light came on sooner after each time I pulled the fuse, I should have taken the car to Autozone, they do free checks.

Anyway, I cleaned the MAF sensor with contact cleaner, I could see the wires in the sensor had dirt on them, the cleaner cleaned the MAF right up, and no more 'Check Engine' light.

By the way, be careful when taking the MAF sensor off of the airbox,

the two screws that hold the sensor onto the airbox are really tiny, bout a little larger then an ants brain default_blink

Good Luck with the Corolla! default_biggrin

ALso, a BIG thanks to fishexpo101 and the others with the information on Corolla's, you have helped me in many ways, and provide information needed.

I wanted to post this in one the post pertaining to cleaning the MAF sensor but the search is not working on this site... oh well

I wanted to post this in one the post pertaining to cleaning the MAF sensor but the search is not working on this site... oh well

well suprise suprise...that was supposed to be fixed now. maybe it wont take several months before they get around to "fixing" it again. dont hold your breath...

glad you got the help you needed from users here atleast.

Guest Mikeyworks

I did clean the MAF last night and it CEL went right away. I hope this fixes the problem.

I will update if it comes back.

Mikey

Guys,

I had the exact problem for 2 years on my 2000 VE. When the car was in warranty they replaced the charcol canister from the fuel tank. After 3 years and well out of warranty the check engine light came on. I lived with it for a wile, hesitation on cold starts, if the car colled for 20 minutes it hesitated until warm. I found the technical bulleting from toyota an the problem is the MAS sensor. I orderd itfrom autozone and replaced it 2 days ago. My CAR RUNS LIKE NEW AGAIN:) NO CHECK ENGINE LIGHT!

**Occasional problems on this vehicle are failures of the Mass Air Flow (MAF) Sensor and the Canister Closed Vacuum Switching Valve or Pressure Sensor Vacuum Switching Valve. Failure of the MAF Sensor and the Canister Closed Vacuum Switching Valve or the Pressure Sensor Vacuum Switching Valve can cause the check engine light to illuminate. On some vehicles the MAF Sensor can be cleaned and will not need to be replaced. The cost to replace the Canister Closed Vacuum Switching Valve is estimated at $44.18 for parts and $45.50 for labor. The cost to replace the Pressure Sensor Vacuum Switching Valve is estimated at $75.68 for parts and $65.00 for labor. The cost to replace the MAF Sensor is estimated at $151.10 for parts and $58.50 for labor. All prices are estimates based on $65 per flat rate hour and do not include diagnostic time or any applicable sales tax.**

AUTOZONE INFO:

http://www.autozone.com/

CARDONE MASS & VANE MASS AIR FLOW PART #74-50010 1 $65.00-CORE + $71.99 = $136.99

Guest mattaveli

same problem as mine took it to toyota cost 6 dollars to clean the carbon off the maf sensor car ran like new

Bikeman982

Seems like the common solution is to clean or replace the MAF sensor.

Guest T-Comm

sorry to bring this thread back from the dead, but i've been having hesitation problems in my '01 corolla that seem to be related to the MAF but i'm getting no codes.

i've cleaned the MAF and other sensor near it with TB cleaner but am still having hesitation problems. seems worst when just started, but will also hesitate upon throttle tip-in in.

to me, it seems like a fuel pressure/delivery problem but i would like some more info on common problems before jumping into that line of thought.

thanks for any input.

Bikeman982

sorry to bring this thread back from the dead, but i've been having hesitation problems in my '01 corolla that seem to be related to the MAF but i'm getting no codes.
i've cleaned the MAF and other sensor near it with TB cleaner but am still having hesitation problems. seems worst when just started, but will also hesitate upon throttle tip-in in.
to me, it seems like a fuel pressure/delivery problem but i would like some more info on common problems before jumping into that line of thought.
thanks for any input.

It does not sound like the same problem this thread discusses. It does sound like a fuel delivery problem, such as the injectors or even the spark plugs not working well.