CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Corolla 2002 , error codes P0171, 0420, 0441 + excessive oil consumption!

Hi
Actually I bought a used Corolla 2002 with 120K which seemed fine and the driving is fine.
After I bought it, I just found out that the seller has removed the check engine light. :frowning:
When I read the ODB codes, It shows three codes of 0171, 0420, 0441. Also I have recently found out that the engine burns excessive amount of oil. (about a quarter per 200 miles).
Actually the driving of the car is fine and as long as I add oil engine it seems fine.
I think all of these errors might be just due to a small problem like a broken valve (since it’s not high milage). It seems that there is no vaccum leak from hoses as well.
Does somebody have any idea what is the problem? and what should I check first?

I really appreciate.

-Jeff

The first thing that needs to be done is to run both a dry and wet compression test. A good engine should have about 190 PSI on a dry test.

The engine might be considered to have astronomically high miles on it based on how it was treated by the previous owner(s). Someone has chosen to dump a headache off and you’re the owner of that headache now.

My gut feeling is that the engine got little maintenance in the past and has become a sludge monster or has been severely overheated; or both. Either one will cause oil consumption.

You mean the seller somehow removed the dashboard bulb for the check engine light? That’s pretty enterprising! Next time you buy a used car, remember that the check engine light is supposed to come on when you turn the key to “on” but before you start it. After you start it, then it turns off. That’s how to tell if the bulb is working.

Google can help you out with the codes. This is what I found with a bit of quick Googling.

P0440 - Evap emission Control system Malfunction
P0441 - Evap Emission Control System Purge flow fault
P0171 - System lean (Bank 1)

So it appears there’s something wrong w/the evap control gadgets, maybe a collapsed hose, or a faulty valve, or maybe its just the gas cap is leaking. Try a new gas cap, see if that works. Maybe you can borrow one from someone who owns the same car, just to test it out. In Calif they always test the seal of the gas cap at emissions testing time. Before I go to get an emission test with my older car, I always wipe a very, very thin layer of oil on the O-ring of the gas cap, and that makes it sea plenty good enough to pass the test.

And the 171 codes says there’s something wrong with the fuel/air mixture. This could be caused by a faulty O2 sensor or MAF sensor among other possibilities. It may be related to the oil use problem. Perhaps the oil is clogging the O2 sensor.

The oil use needs to be confirmed as a burning issue as opposed to a leaking issue. If you in fact burn a quart every 200 miles in this car then the engine is a goner, not worth a dime. This is over the top oil use.

P0441 could be due to overfilling the gas tank.

P0420 plagues Corollas but in many cases, if you go to the dealer and order a rear O2 sensor based on your cars VIN, that may take care of it. It works on most Corolla’s but if yours is burning that much oil, you may need a new catalytic converter. The oil burning will damage the cat and that code is saying that the cat efficiency is low.

P0171 is system too lean. It could be related to the P0420 or it could be a vacuum leak or a dirty MAF.

But the oil consumption is really the big concern here. Maybe you get lucky and the oil is just leaking from valve cover gaskets, bad oil plug gasket, bad filter gasket, broken oil pressure sending unit or something else.

But all these problems combined tell me that this car has been rode hard and put away wet too many times. In some states, you might have some recourse against the seller as they do not allow anyone to sell a car with a known emissions problem.

P0171 is probably a leaking intake manifold gasket; common for this vintage Corolla.
Least of the problems for this car, unfortunately.

I’m with OK4450 on this. The first step is a comnpression check. If these cylinders are as torn up as the oil usage would suggest, forget the “lean” code…the O2 sensor is probably coated with oil residue and giving a false reading, but it’ll just keep happeneing unless the oil burning is resolved…and that’ll cost more than the car is worth.

Re: the EVAP system: the purge flow refers to the system by which the engine when started evacuates gas molecules from the charcoal bed. The fumes are drawn in via an orafice in the throttle body. It’s possible that the EGR system has been so badly contaminated by the EGR system due to the burning oil that everything in the TB is coated and clogged up with carbon.

In summary, first evaluate the engine via the compression check. Post the results and we’ll go from there.

Is it burning a quart every 200 miles or a quart every 800 miles?

" I have recently found out that the engine burns excessive amount of oil. (about a quarter per 200 miles). "

If it’s a 4 cylinder, it only has one bank so the engine is complaining about a fuel mixture problem…A good mechanic can run a real-time scan and sort that out quickly…The evap problem can be deferred until you must pass an emissions test…On your next car, be sure the CEL is working properly before you buy it…

Did you buy this car from a dealer or was it private party?
Do you have any recourse?
What the previous owner did was totally unethical, and if you do confront them, they’ll probably claim ignorance . . .