2001 Toyota Corolla LE: Fuel Vapor Canister & Air sensor check engine light codes/oil low

The pistons in the 1zzfe were revised in 2002 IIRC with more & larger drain holes.

I’ll go slightly off-topic

@kinsha brings up an excellent point, and pretty much sums it up

Some owners are lucky . . . while others do all the right things, and still encounter “the problem”

That’s the whole thing with pattern failures, if you want to call it that. Not everybody will be affected, but there is a pattern, so to speak. And if it happens to you, it shouldn’t be a shock

In the other thread . . . about the SLK350 . . . there were so many potential major and expensive problems with the car, that I recommended against. So many possibilities, that the chance that even one of the problems occurring is pretty good, in my opinion. A bad bet, IMO

I’d rather shop for a used car that doesn’t have any TSBs relating to engine and/or transmission mechanical problems

CR has gotten better, lately. For each used car, they briefly describe potential problems . . . and the solutions . . . and even list a number for the TSB, recall, campaign, etc. If I was shopping for a used car right now, I’d spend a few minutes reading that. And I could hopefully avoid some lemons, by not even looking at certain cars. I suppose this is even more important for non-car people that don’t do their own repairs and maintenance

I remember when CR gave you pretty limited details

I will be in urban area in Iowa. Hope to not run car a lot and let it sit in driveway/street mostly. If I do that, am I supposed to do something like start it once a month for 5 min to keep things copacetic? I know a trickle charger is available.

You guys are right topping off is penny wish and pound foolish but I did it. Found a cheap as hell secret gas station and wanted to gorge. Another time found double cheap central valley station and since I was REALLY close to empty (needle well below E) I decided to test capacity. Pumped in 14.5 gallons when the manual says it will hold 13.2. Finally gave up trying to top it off. Somebody said the tank neck must hold the extra gallon plus.

Called mechanic who changed oil thinking maybe he meant half-quart low not half-quart left. Word got back to me that he said I only had one quart left. Well. I’ve driven 1,000 miles since oil change and other day oil in morning before starting was right in middle of the marks on dip stick. This morning was barely more towards the bottom mark so…if it was losing oil shouldn’t I see more loss at 1,000 miles? I am assuming this is a linear process - maybe not?

Previous corolla 1999 VE I was told of low oil by oil changers around 190-200k and was able to monitor and gradually add more oil until it was using what I thought of as a medium amount around 220k. Then I got new headlights and wheel bearings etc and within a week or so some lady failed to yield and totaled it. That was 4 years ago and the rib muscles under the seat belt still hurt at times (she drove into me on driver side).

Tangent: Driving to Iowa from California. Moving van won’t work I need to triage and pack stuff myself over time. PODS wanted 1 month at 2.2k. U-haul wants 1k (buy hitch for $330, rent 5X8X5 trailer for $650, I think $20 a day over a week). I am less than halfway through packing, throwing away etc, and although I thought I could do two roundtrips (yes a long way but I like seeing places) its looking like I will need to use a U-haul. Any other options?

Found a Toyota-in-name-of-shop mechanic who will check evap problem before next year. Leaving car there tonight to wedge into his schedule so he can look at it tomorrow. Guy didn’t say anything when I mentioned the scan tool in mode 6 etc, he just cocked his head to the side. This place has serviced my brother’s Sienna for years.

Again, topping off could well lead to some expensive repairs. You saved 10 cents and could have hundreds of dollars in repairs. This is a habit you should break unless you want to continue repairs of the evap system.

Re U-haul, what does your owners manual say about towing?

Dunno what owner’s manual says, u-haul guy entered 2001 corolla LE on computer and it apparently came up with 2,000 lbs and particular hitch. 5X8X5 trailer rated at 1,100 lbs and apparently you would have to fill it with very heavy stuff to get to 1,100 lbs. I have probably 20 cubic feet of clothes to give to Goodwill etc that will lighten things.

New mechanic said he tested everything and EVAP is definitely charcoal canister and air sensor problem is not related.

Charcoal canister: Needed to pass smog in California but smog is not done in Iowa so I could just not replace it as it would not hurt anything otherwise. Said no it won’t just dry up eventually and yes caused by topping off. So how bad will I be polluting things by not replacing it? Also, why does design allow topping off to foul it? All cars like that?

Air Sensor: Could just be dirty. He cleaned it off and said buy a $15 scan tool on Amazon and read future check engine lights to determine if air sensor code comes back, if it does then replace.

Oil Loss: Doesn’t know why I don’t see more oil loss by now if I was down to a quart after 4.8k but said my engine model known to blow oil past piston rings. Said sitting idle for a month not related.

Also said alignment should not be needed when tire changed (earlier mechanic replaced right rear with sidewall damage with slightly different size tire I had around - 175 vs 185 - at high speed ride doesn’t seem as smooth so could just be due to difference in size and tread depth).

Also said sorry but duct tape best solution for loose center console lid. I used duct tape but it easily comes off, even went to a Pick-n-Pull place with 7 corollas and NONE had a useful lid.

New mechanic charged me nothing and potentially saved me $600. I see chocolate in his future.

Charcoal canister: So how bad will I be polluting things by not replacing it? Also, why does design allow topping off to foul it? All cars like that
?

It’s not a serious pollution thing. You might be allowing a little gasoline vapor to escape into the air is all. A problematic evap system can affect drivability and engine performance though, so if you notice anything like that, you might still have to fix it. I’m not sure if what the mechanic said about it drying up and fixing itself is accurate or not. I expect a gasoline saturated evap canister will suffer some permanent damage. How much it can cure itself after drying up? Not sure.

Most cars will allow overfilling, and so the canister will get saturated if the owner does that. I think some newer evap designs prevents the owner from over-filling. I’m not sure what happens if you insist, and keep pumping gas in. Maybe instead of flowing into the canister, gasoline pours out onto the cement at the gas station. I’m not sure which is worse … lol …

I think when you say “air sensor” you mean “O2” sensor. If so, suggest you use “O2” sensor as it might be otherwise confusing when speaking to mechanics.

I haven’t noticed any difference in performance but then again I don’t know much about cars. What I notice is that the car seems to have more noise and vibrations at high speed than it used to. Last night I was hearing what seemed to be extra noises all over especially the whole front dash area, the steering wheel seemed to have extra shake. I was thinking I should get somebody who knows cars to take it up to 65-70 and see what they thought. Say 45 mph and below seems normal. I’ve pumped up all tires to low 40’s as I am moving boxes every night which must add a couple hundred pounds (moving residences). Read something about having one wheel with extra tread you can get it shaved off but it will rub off anyway after awhile. The replaced right rear has more tread than the other 3 (Michelin Defenders).

Check engine light has gone on and off twice now I think. Huh. Scanning tool hasn’t arrived yet.

Is it the O2 sensor, not the air sensor? I don’t know, I’ve just been parroting what I heard from mechanics.

You should not have the tires at that high a pressure for a few hundred pounds of load. That is just the weight of one passenger. Restore them to the correct pressure and I suspect your noise and vibrations will go away.

“one wheel with extra tread you can get it shaved off but it will rub off anyway after awhile” If that tire is on a non-driven wheel, that’s OK. But it won’t wear off. It might have a small influence on high speed maneuvers.

Scan tool still not here. After 2,000 miles yes engine needed a quart of oil. Is that considered low, medium, or high oil usage?

Pretty sure right side wheel needs new bearings but ain’t got the time. Otherwise, vibration seems not as bad. Maybe was related to wet roads?

Not car related: Nightmare month to month San Francisco rental agreement “jointly and severally responsible” clause seems to make me liable for perpetuity if other 2 co-tenants do not want to quit rental agreement. Tenant help places, my own lawyer, his holiday replacement lawyer, nobody giving me helpful information on how to stop being liable until I die. Anybody happen to have experience with this?

Driving with bad wheel bearings is dangerous. Keep your speeds down to 10 MPH or less.

1 quart in 2000 miles is not low usage, but it’s still acceptable

I’m a small scale landlord myself . . . I live in one house, and I’ve got a tenant in the other . . . and I think this is not the place to get advice for that kind of stuff

BillRussell - How to diagnose if noise is wheel bearings?

db4690 - Where should I go for such advice?

Try a landlord forum.
And best of luck.

@SFer

bad wheel bearings will often result in a roar type of noise

Then again, tires with choppy tread will also produce similar noises

Is your steering wheel shaking at freeway speeds . . . if so, the first thing you need to do is have your rims and tires balanced, as needed

You could put your car on 4 jack stands. Then carefully turn each tire by hand. It should turn smoothly. If one of them seems rough when you’re turning it, the bearing may be bad

Grab the tire at the 12 o’clock and 6 o’clock positions and try to move it it and out, with moderate force. It should NOT feel loose

a mechanic with “chassis ears” could also narrow down if the bearings are bad, and which one

Sounds like the guys have provided their usual level of diagnostic prowess…and I have to agree with them.

You must have your exhaust leaks repaired to begin with many of the 400 codes are associated with leaks…both exhaust and or vacume hoses… With an exhaust leak you will usually post a P0420 catalyst inefficiency code…I could go into the why’s of all that but thats not needed.

The exhaust and EVAP system need to be checked over… You already explained several symptoms that would cause the codes you are having. Repair any exhaust leak…then move toward evap system is what I would do. The exhaust leak issue is something easy to detect…without leaks the EVAP issue will be more easily diagnosed as well. This and what the other good people here have mentioned will or should have you fixed up. EVAP issues can be a PIA to diagnose sometimes…thats what the “Smoke Machine” is for however… Looks like you have more than enough advice without me muddying the waters further. Hope it works out for you…

Blackbird

Scan tool finally came in. P0171 lean mix now and pending. Mechanic who cleaned the mass air filter put a new one in but same code came back same day. I had to drive to Iowa next day and he needed more time than that to research the problem so he put the old one back in and said the engine can compensate - won’t hurt it.

Drove to Iowa on I-80. Rode great the whole way with check engine light on the whole time. Some sections of Wyoming at 80 mph were smoother than Highway 101 at 55 mph! Drank a quart and a half of oil.

Mechanic in Iowa kept the car several days - something about intermittent loss of power. Got a new set of tires (Cooper, old ones could have gone on a little longer but I figured I going to be on a lot of snow and ice…). Said the right side noise was a broken motor mount - replaced. Said the check engine light was due to the mass air filter and the air intake gasket which were both replaced, and after keeping the car a few more days the oxygen sensor was replaced (said it was reporting at half the speed it should have). Car feels and sounds better.

Day later intermittent loss of power as I drove it home over about 5-8 min (I have not experienced this before!). Pushing accelerator and rpms go up but not engine for a few seconds. Sometimes I think the rpms went down, anyhow it took way way longer for engine to respond than it should and wasn’t that smooth. &^%$#@! Reminded me a bit of water in the gas symptoms I had when I had a geo metro. Next day drove car around and no problems, drove it hard accelerating to get to meeting I was late etc. When I came back from meeting noticed check engine light back on! My old friend P0171 now and pending. Mechanic can’t get to it before Wed.

Has the intake manifold gasket been replaced?
A common cause of P0171 in this vintage Corolla.
My apologies if this has been mentioned already in this long thread.

I think mechanic used the term “air intake gasket” as one of the parts he replaced. On the bill it reads “Manifold Gasket set (Intake)” under “Part Description” and “INTAKE MANIFOLD GASKET - Remove and Replace - All Applicable Models” under “Labor Description”.

Mechanic had it for another 3 days and still could not figure it out. I had to leave for California. After 20 minutes on the interstate I pulled off and had to wait almost a minute at a stoplight. When the light turned green I hit the accelerator and had the loss of power problem again for a few seconds. Since then I’ve gone over 1,500 miles and haven’t had the problem again.

@SFer

You need to find a different mechanic . . . it kind of sounds like this guy is just guessing

Did he even smoke test it?

Any leak after the mass airflow sensor and before the upstream sensor is false air . . . even a leak at the exhaust manifold flange gasket can cause P0171. Seen it a few times

Did he measure fuel pressure? I’ve seen P0171 caused by low fuel pressure