Which parts fail
Components named in complaints (fuel pump, injectors, fuel tank, hybrid and EV propulsion).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2003 Toyota Tacoma owners, lightly cleaned up (personal details are redacted by NHTSA).
While driving on the highway, I experienced an issue with the vehicle's performance under moderate acceleration (approximately 3000 RPM). The engine will no longer output power that is proportional to the amount I am requesting with the gas pedal. Once the issue occurs, the maximum power output is only 2000 RPM with the gas pedal fully pressed. The issue is occasionally resolved by shutting the engine off and waiting a few moments. The check engine light comes on with the code po120. The code translates to a faulty throttle position sensor but Toyota will not replace the $60 sensor individually, they will only replace the $1,200 throttle body that includes a new sensor.
Tl* the contact owns a 2003 Toyota Tacoma. The contact stated while the vehicle was parked in the garage, rodents ate the fuel line causing a fuel leak. The contact stated no warning light was illuminated. The vehicle was taken to haley Toyota of roanoke (1530 courtland rd ne, roanoke, va 24012) where it was diagnosed with the fuel line needing to be replaced. The vehicle had been repaired twice however, the issue recurred. The manufacturer had not been informed of the failure. The failure mileage was approximately 75,000. The VIN was unavailable.
I was driving down the highway experience loss of power such as fuel push the throttle down a couple of times it pick back up happened to more times within 10 mi1nutes it did not throw a code been checking it May relate to a throttle body problem been reading about problems with the throttle body do not want this to happen in heavy traffic or pulling out in front of traffic please let me know what or how to take care of this problem
After driving for approximately 2 hours, on three separate occasions, the vehicle would intermittently lose significant power. It felt as though I had taken my foot off the throttle. After my own investigation, I learned that Toyota has a history of this problem, particularly with their 2003/2004 model Tacoma's. Evidently, their accelerator pedal position sensor (part of their throttle by wire design) fails. This created a few serious safety situations for me when the throttle failed to respond when needed. After reporting this to the dealer, they inspected the vehicle and did determine the apps was at fault. Numerous accounts of this happening with other owner's is readily available via the various bulletin boards on the web. Compounding the issue, is the fact that this sensor cannot be replaced without replacing the entire throttle body assembly at a cost of $1000 or so. …
I'm filing the compliant to acknowledge the fact that these older fly by wire throttle bodies have a faulty tps that is only replaceable as a whole new throttle body. The cost on them is between 700 to 1000 dollars. My Tacoma do have a faulty tps on it. I'm waiting to save up enough money to replace the throttle body however, there have been numerous times that upon pulling out into traffic it has acted up. When this happens you get a very bad hesitation or lack of acceleration to the point of endangering myself and other drivers. The hesitation has lasted as long as 3 to 5 seconds before the throttle will finally respond. The condition will only happen during hot summer months. Thank you for your time and would like the see this looked into and or resolved. I will be able to replace the throttle body because I work at a dealership and get the parts at cost. …
My truck was part of the frame recall and I had the frame replaced in 2010, since then I have had to pay to replace other rusted parts that were not "part of the recall". First the spare tire mount rusted off and the tire fell out from under the truck while driving. Next the entire exhaust needed to be replaced as it too had rusted out. Last year to pass inspection I needed to pay $1600.00 for a catalytic converter. This year I cannot pass inspection as the check engine light is on and despite 2 attempts to find the problem (and $200.00 later) the light remains on. The suspicion is the gas tank is rusted "at the top" and will cost me $1800.00 to replace. I just received a "preliminary" recall for the spare tire mount, I imagine I will receive a recall notice in a few years for the gas tank as well. …
Intermittent check engine light and rough idle - 2003 Toyota Tacoma 2.7l auto, double cab, 55K miles check engine light came on. Took vehicle to local chain shop who diagnosed error code po511 - idle air control valve (iacv). Toyota parts department prices this part at $226 and service manager indicated $249 for labor (not including tax). Vehicle currently has 55K miles on it and "engine" should be covered by 6 yr/60K mile powertrain warranty. Took vehicle to dealer (to have other recalls corrected) who indicated a $90 fee was required just to diagnose check engine light. Toyota customer service indicated the iacv was only covered to 3yr/36K and that I should pay dealer fee and seek "factory assistance" for any costs to repair. …
The problem that exists is on my 2003 Toyota Tacoma. It will all of a sudden lose power and have no throttle response, almost as if it was hitting an engine governor. The rpms usually drop anywhere from 200-500 and then comes back up. The power would slowly come back after keeping my foot on the throttle. It consistently does it after accelerating out of an intersection (usually around 25 MPH or while cruising (around both 45 MPH or 75 MPH) on the highway. This drop of power or lack thereof is a huge safety issue, especially when pulling into an intersection or needing quick acceleration to avoid an accident. I have read about many others with the same issues with their late model tacomas. The parts to fix the issue are very costly and the problem seems to be widespread. [redacted] request research.
Toyota Tacoma, 2003 acceleration drops to 25% inadvertently. This is a well documented issue on several of the Toyota Tacoma bulletin boards yet Toyota has done nothing to remedy this highly dangerous situation. The accelerator pedal position sensor fails and drops the acceleration to 25% without warning. This happened to me while doing 75 on the highway and I was nearly rear ended by a semi truck! I have complained to Toyota with no response. This is well documented and needs to be addressed!
While driving in traffic the throttle stuck at above normal idle and the check engine light came on. I was able to exit the traffic but the idle would not come back to normal curb idle. What my mechanic has told me is that the throttle body assembly has failed and they can only get the part from the dealer. If this had happened on the freeway the outcome could have not been so good. I hope Toyota is aware of this problem and going to address the situation.
Related recalls
Fuel system, gasoline › Delivery › Hoses, lines/piping, and fittings
On certain pickup trucks, during side impact ncap test (I.e. Lincap test), a flange at the rear end of the double cab body deformed and interfered with the fuel inlet hose that connects the fuel filler pipe and fuel tank, resulting in damage to the fuel inlet hose.
Remedy: Dealers will install a fuel hose protector on the body flange. Owner notification began June 3, 2003. Owners who take their vehicles to an authorized dealer on an agreed upon service date and do not receive the free…
Fuel System complaints in other Tacoma years
Frequently asked questions
How common are fuel system problems on the 2003 Toyota Tacoma?
NHTSA has 22 complaints about the fuel & propulsion system of the 2003 Toyota Tacoma, 6% of the model year's 360 complaints. The component named most often is delivery › hoses, lines/piping, and fittings (1 mentions).
Is there a recall for 2003 Toyota Tacoma fuel system problems?
Yes — NHTSA recall 03V-189 (hoses, lines/piping, and fittings, May 19, 2003). Recall repairs are free at authorized dealers.
At what mileage do 2003 Toyota Tacoma fuel system problems start?
Half of the complaints with a recorded mileage happened before about 80,000 miles, and 5% before 25,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.