Check engine light

Your fuel lmileage may not be the best and stuff wont' work right probably. Up t o you to drive it. If it's only a n O2 sensor it won't hurt much.

Check engine light on

https://www.2carpros.com/articles/service-engine-soon-or-check-engine-light-on-or-flashing

Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to turn on-This is your starting point of diagnosis,finding out what's going on.

Carbon build-up at 19000 miles? How would you expect people to buy that? Get back to the service dept and insist they find the solution to your problem.
Something is definitely wrong with the engine and if it occurred twice, it is going to happen again and the problem to be covered under warranty.

Replace cap. Add oil and you will have to clean off the motor. A sensor most likely got wet.

What was the code.

Roy

Scan fro codes and check fuel pressure with a gauge auto parts rent it.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Those engine codes do indicate faults in these components. The estimate is also right on for these repairs. The parts is the most expensive, with the canister costing $300 alone. Add the fuel cap and 2 hours of labor at approx. $75 / hour this adds up very close to your estimate

Hi starwisher115,

When the MIL indicates, trouble code(s) would be stored in the Power Control Module. You would need to retrieve the trouble code to understand what is cauing the MIL to show.

Get a free scan done at Autozone and let me know the exact trouble code so I can assit in solving the problem.

Here are the description of the code and diagnostic procedures.

DTC P0171 OR P0172: SYSTEM TOO LEAN/RICH (EXCEPT CALIF. EMISSIONS)
Circuit Description
Fuel trim refers to feedback compensation value compared against basic injection time. Fuel trim
includes short-term and long -term fuel trim.
DTC P0171 is set when fuel trim is driven rich beyond a certain value. Possible causes are:
à   Air induction system malfunction.
à   Fuel injector restricted.
à   Defective Manifold Absolute Pressure (MAP) sensor.
à   Defective Engine Coolant Temperature (ECT) sensor.
à   Improper fuel pressure.
à   Exhaust system leak.
à   Heated oxygen sensor No. 1 circuit is open or shorted.
à   Defective heated oxygen sensor No. 1.
à   Defective ECM.
DTC P0172 is set when fuel trim is driven lean beyond a certain value. Possible causes are:
à   Fuel injector restricted or leaking.
à   Defective Manifold Absolute Pressure (MAP) sensor.
à   Defective Engine Coolant Temperature (ECT) sensor.
à   Ignition system malfunction.
à   Improper fuel pressure.
à   Exhaust system leak.
à   Heated oxygen sensor No. 1 circuit is open or shorted.
à   Defective heated oxygen sensor No. 1.
à   Defective ECM.

Diagnostic Aids
When DTC P0171 is recorded, actual air fuel ratio is too lean. When DTC P0172 is recorded, actual
air fuel ratio is too rich. If vehicle runs out of fuel, DTC P0171 will be set. Using scan tool, read
freeze frame data. Freeze frame records engine conditions when malfunction is detected.
Diagnosis & Repair
CAUTION: If ECM replacement is instructed in following testing, always ensure ECM connectors and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction.
NOTE: Heated oxygen sensor No. 1 refers to oxygen sensor closest to engine block. Heated oxygen sensor No. 2 refers to oxygen sensor farthest
from engine block.
1. Ensure oil dipstick, oil filler cap, PCV system and all other air induction system components are intact and operating properly. If problem exists, repair as necessary. If problem does not exist, go to next step.
2. Check fuel injectors. If problem exists, repair as necessary. If problem does not exist, go to next step.
3. Check Manifold Absolute Pressure (MAP) sensor and Engine Coolant Temperature (ECT) sensor. If problem exists, replace appropriate component. If problem does not exist, go to next step.
4. Check spark and ignition system. If problem exists, repair as necessary. If problem does not exist, go to next step.
5. Check fuel pressure. If fuel pressure is not within specification, repair as necessary. If fuel pressure is within specification, go to next step.
6. Check exhaust system for leaks. If problem exists, repair as necessary. If problem does not exist, go to next step.
7. Connect scan tool to Data Link Connector (DLC) No. 3. Start engine and increase engine speed to 2500 RPM for approximately 90 seconds. Let engine idle. Using scan tool, monitor heated oxygen sensor No. 1 output voltage. Voltage should alternate repeatedly from less than.4 volt to more than.5 volt. If voltage is as specified, go to step 9. If voltage is not as specified, go to next step.
8. Check for open or short in wiring between ECM and heated oxygen sensor No. 1. If problem exists, repair wiring as necessary. If problem does
not exist, replace heated oxygen sensor No. 1.
9. Perform test drive confirmation, then go to next step.
10. Clear and recheck for DTCs. If DTC P0171 and/or P0172 are displayed again, replace ECM. If neither DTC P0171 nor P0172 is displayed again, go to next step.
11. Vehicle either ran out of fuel or problem is intermittent. Check component and ECM connections.

MAF is plugged into air cleaner housing and can be remove after taking out the holding bolts. No tricks in a straight forward job.

An error has been detected by the engine management system and you need a scan to retrieve the trouble code, proceed with repairs to rectify the fault and erase the trouble code to have the MIL go off.

RAV4's are great cars, and normally very reliable, buying second hand is always a gamble as you often do not know the service history of the car, if you like it, ask the owner if you can get it checked over by a mechanic first, if they are honest and they feel the car is in fair condition, they should not have a problem, if they say no, well don't bother as they may be trying to hide something, all cars have check systems now, these are internal self test systems that tell you when you have a problem, the mechanic can do a scan to see what has been set in the past and if there are any current codes as not all codes will set a check light.