Fuel System
Check engine light, sensors (includes O2 or oxygen sensor), emission control devices (includes EGR), engine computer, engine computer, fuel cap, fuel gauge/sender, fuel injection system, fuel pump, fuel leaks, stalling or hesitation.
What Owners Say
"Periodic faulty reading on Check Engine sensor Replace the catalytic converters"
Anonymous, NY (2001 Toyota Sienna LE 3.0-L V6)"All catalytic converters have failed or are failing"
Steven K., FL (2001 Toyota Sienna LE 3.0-L V6)"Check engine light came on 3 times in 3 months; each time it was a different component of the emission system; charcoal canister, a couple of valves, hoses and a gasket"
Anonymous, CA (2001 Toyota Sienna LE 3.0-L V6)"The check engine light comes on periodically and is reset at the dealer. when the check engine light comes on, the Vehicle Stability Control stops working. The problem is reported as the catalytic converter failing"
Anonymous, CO (2001 Toyota Sienna LE 3.0-L V6)"had to replace catalytic converters. Both"
Anonymous, AZ (2001 Toyota Sienna XLE 3.0-L V6)"Same as above"
Daniel S., ON (2001 Toyota Sienna XLE 3.0-L V6)"Catalytic converter needed replacing"
Ken W., NC (2001 Toyota Sienna XLE 3.0-L V6)"Catalytic converter and charcoal canister failed. Very expensive repair"
Jack S., IL (2001 Toyota Sienna XLE 3.0-L V6)"Check engine light keeps coming on even though I replace both CATS. Might be problem with the computer module as per technical bulletin"
Anonymous, OR (2001 Toyota Sienna XLE 3.0-L V6)"The emission light is always on even after getting it fixed."
Anonymous, (2001 Toyota Sienna XLE 3.0-L V6)"Emission control lines, sensors, on fuel tank leaked causing fumes. Had to pull tank out twice to repair. Still smell fumes at times around rear of vehicle, can’t find anything wrong"
Gary P., CA (2001 Toyota Sienna LE 3.0-L V6)"Catalytic converter failure"
Anonymous, FL (2001 Toyota Sienna LE 3.0-L V6)"Don't think it will pass inspection next September if I don't get it fixed before hand. Other than that this has been the best vehicle I have ever owned. I will always buy a Toyota at this point"
Patricia W., NY (2001 Toyota Sienna LE 3.0-L V6)"The vehicle at random will stop allowing gasoline fill-ups due to the fuel "evap" system being clogged somehow. Gas pumps (at all stations tested) will stop continuously after only pumping a quarter gallon to a half gallon of fuel, even at slowest setting. Only time fixes the issue until it starts occurring again with no predictable pattern. The fuel tank has never been "topped off""
Anonymous, WA (2001 Toyota Sienna XLE 3.0-L V6)"The check engine light kept coming on. The dealer worked on the emissions system components three times before they finally found a leak in one of the hoses"
Anonymous, CA (2001 Toyota Sienna LE 3.0-L V6)"Check engine light error indicated loose gas cap was really a carbon filter"
David C., MD (2001 Toyota Sienna 3.0-L V6)"vacuum system leak"
Anonymous, AZ (2001 Toyota Sienna XLE 3.0-L V6)"EVAP system slow leaks. Too many possibilities, lots of plastic parts. Expensive to fix, costs thousands to track down, didn't work, track some more, etc."
John P., AZ (2001 Toyota Sienna XLE 3.0-L V6)"Had to be replaced"
David V., IL (2001 Toyota Sienna 3.0-L V6)"Both Original engine sensors replaced in 2004. Both Aftermarket sensors replaced in 2014 Each time they failed within months of one another"
Anonymous, VA (2001 Toyota Sienna XLE 3.0-L V6)"O2 sensor had to be replaced after check engine light came on. After replacement, no problem"
Anonymous, GA (2001 Toyota Sienna LE 3.0-L V6)"engine light check comes on- apparently connected to gas cap failure so no real issue with emissions, but need to disconnect electrical then drive for 100 miles to pass inspection"
Anonymous, MA (2001 Toyota Sienna XLE 3.0-L V6)"Air/Fuel Sensor failed"
Anonymous, MN (2001 Toyota Sienna XLE 3.0-L V6)"O2 sensor failure, VVT sensors(2) knock sensors 2 All failed within last 50,000 The car now has 406,000km and has been the best vehicle I have ever owned. These problems are expected on a car this age"
Edward S., ON (2001 Toyota Sienna LE 3.0-L V6)"Sensor caused Check Engine Light, needed to be replaced"
Anonymous, NJ (2001 Toyota Sienna LE 3.0-L V6)"Engine check light kept coming on"
Anonymous, MA (2001 Toyota Sienna XLE 3.0-L V6)"Engine light comes on to indicate a fuel fumes leak is detected. Mechanic says that the sensors are too sensitive as he cannot locate the leak and says it would be cost prohibitive to look for it. The vehicle runs fine, but the engine light also turn"
Daniel S., ON (2001 Toyota Sienna XLE 3.0-L V6)"Failed emission test for last two years even after extensive work on the exhaust system"
Pamela-Edward T., MD (2001 Toyota Sienna 3.0-L V6)"Same response as previous item"
Anonymous, OR (2001 Toyota Sienna XLE 3.0-L V6)"There are three Catalytic converter units on this van and it took over 2 years to get check engine light code to clear for good. Part of problem was oxygen sensor downstream of the last converter unit. Turned out that the converter unit attached to"
Alan B., TX (2001 Toyota Sienna XLE 3.0-L V6)"Engine light comes on...had two of the three sensors replaced...light still on...replacing the 3rd sensor soon"
Anonymous, MN (2001 Toyota Sienna 3.0-L V6)"Sensor repair was expensive, and the repair did not entirely solve this issue"
Anonymous, MD (2001 Toyota Sienna XLE 3.0-L V6)"Check engine light came on October 2019. Car parts store read the code for inefficiency of the O2 sensor past the catalytic converter. I purchased the part, removed the old one, and the new sensor turned of the CEL. No issues since."
Anonymous, NY (2001 Toyota Sienna LE 3.0-L V6)"I don't understand the connection between the previously described caution lights and the transmission - the van was performing flawlessly but needed a 'Smog Check'???"
John P., CA (2001 Toyota Sienna XLE 3.0-L V6)"it has required service on the sensors 3 times since it was new. As I recall, each time it cost about $1500 to replace the faulty sensor"
R M., SC (2001 Toyota Sienna LE 3.0-L V6)"had to replace the o2 sensor twice,all others once. cost 750.00 bucks"
Anonymous, MO (2001 Toyota Sienna LE 3.0-L V6)"had to replace 4 sensors, cost $750.00"
Carl C., MO (2001 Toyota Sienna LE 3.0-L V6)"heated O2 sensors on exhaust manifold banks have heater elements go out on them. Didn't notice any change in engine behavior or mileage, but Check Engine light was on for a year before I replaced."
Anonymous, UT (2001 Toyota Sienna LE 3.0-L V6)
"Check engine light comes and diagnostics indicate emission problem"
Anonymous, NJ (2001 Toyota Sienna LE 3.0-L V6)