Before you buy a used Toyota Corolla (XII).

Look out for: Poor acceleration and strong jerking, misfires and limp mode; at high mileage, loss of power and higher consumption from carbon on injectors, valves and intake.

Ask them to check: Read misfire codes and check the coil date; ask for a goodwill replacement; clean the intake if there are deposits.

Look out for: In sub-zero temperatures with many short trips: milky or discoloured oil on the dipstick and under the filler cap, an “Oil Pressure Low” message on the instrument panel and the engine warning light. Codes P05202A (oil pressure sensor stuck) and P052477 (oil pressure too low).

Ask them to check: With the oil-pressure warning, stop the engine and do not carry on until it is checked. The garage first pressure-tests the cooling system to rule out an internal leak; if there is none, it changes the oil and filter, wipes the milky residue off the cap and checks with the engine warm (coolant at about 50 °C) that the warning and codes do not come back. If they do, the diagnosis must continue with the workshop manual.

Look out for: The engine warning light (MIL) comes on. The engine computer stores codes P210015 (throttle actuator motor circuit shorted to battery or open), P210019 (throttle actuator motor current too high) or P211172 (throttle stuck open).

Ask them to check: Read the full codes (with their last two digits) and ask Toyota whether there is a newer engine-computer program for your VIN before replacing the throttle body. If the code returns after reprogramming, check the throttle connector and wiring.

Look out for: Hybrid battery cooling maintenance message, warning light with codes P0A80 or P0A7F, a noisy fan and less electric assistance; if ignored, the battery ages faster.

Ask them to check: Clean or replace the filter and clean the fan before condemning the battery; keep the intake grille clear. At the garage, read the codes and, if needed, install the software Toyota specifies.

Look out for: Vibration in the steering wheel and the pedal when braking, even gently and at any speed, often shortly after wheels, pads or discs were changed.

Ask them to check: Ask the garage to loosen and re-tighten the nuts with a torque wrench, to the manual's torque and in a star pattern, and to measure whether the discs have been left warped; if so, they will need skimming or replacing.

Look out for: A starter battery that fails early on the first cars; seized and rusty rear brakes, especially on hybrids; a brake servo that can fail on 2019 cars (more pedal effort); an eCall that does not activate.

Ask them to check: Check the campaigns by VIN; brake hard now and then to clean the rear discs; test the battery.