P0068: MAP/MAF – Throttle Position Correlation
Key takeaways
- P0068 means the air the engine is actually taking in, measured by the MAP or MAF sensor, doesn't match what the throttle position says it should be.
- An air leak after the throttle or airflow sensor and a dirty throttle body are the most common causes.
- It is usually safe to drive, but if the car drops into reduced power or stalls, keep trips short and get it checked.
- Several makers fixed P0068 with engine-computer software, so ask about a bulletin before replacing a throttle body.
What P0068 means
The engine computer is seeing more (or less) air going into the engine than the throttle opening says there should be. Scanners call it MAP/MAF – Throttle Position Correlation. The computer knows how far the electronic throttle is open, and it knows engine speed, so it can predict how much air should be flowing. It compares that prediction with the manifold absolute pressure (MAP) sensor, the mass airflow (MAF) sensor, or both. When the two disagree by more than the maker allows, it sets P0068. Most often the extra air is sneaking in somewhere the throttle doesn’t control.
Is it safe to drive?
Yes, usually, for the short term. Many cars run normally or close to it, maybe with a high or surging idle. Some go into reduced power mode or limit top speed to protect the engine, because the computer no longer trusts its air readings. What changes the answer: stalling, reduced power in traffic, or a flashing check engine light. Keep trips short and get it checked if any of those show up.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Vacuum or intake leak after the throttle or airflow sensor (hose, intake boot, intake gasket, PCV) | Hissing at idle; idle higher than normal; smoke test | $50–$400 |
| Dirty throttle body | Carbon ring around the throttle plate; improves after cleaning and relearn | $80–$200 |
| Dirty or failing MAF sensor | Airflow reading off for the engine size at idle and cruise | $20–$60 to clean; $150–$400 to replace |
| MAP sensor, its hose or port | Key-on MAP doesn’t match barometric pressure; cracked or plugged hose | $100–$300 |
| Engine software | A bulletin for your make, model and year names P0068 | $100–$200, often $0 under warranty |
| Wiring or connector at a sensor or the throttle body | Signal drops when the harness is wiggled; corroded pins | $100–$250 |
| Failing electronic throttle body | Its two position sensors disagree, or it still reads wrong after cleaning | $300–$700 |
On turbo engines, a leaking intercooler pipe or boost hose belongs in the first row too.
What to check first
- Look and listen. Check every intake hose and boot you can see for cracks or loose clamps, make sure the oil cap is on tight, and listen for a hiss at idle.
- Read every code. P0068 with P0101 points toward the MAF; with P0106 toward the MAP sensor or a leak; with P2135 or P0121 toward the throttle position sensors.
- Smoke test the intake. It finds leaks you can’t hear.
- Clean the throttle body and run the idle relearn your car needs. Then clean the MAF sensor with dedicated MAF cleaner.
- Check for a bulletin before buying a throttle body.
- Clear it and drive. If it stays off for a week of mixed driving, you’re done.
The bulletins show a clear pattern of software. Kia’s fix for the 2019–2020 Forte 2.0L is an engine computer logic update plus cleaning the electronic throttle; Mitsubishi reprograms the engine computer on the 2018 Eclipse Cross (where P0068 limits speed to 62 mph) and has a cold-weather fix for turbo Lancer Evolutions; and Ford has a bulletin for 2018–2019 Mustang 2.3L EcoBoost cars driven above 3,500 feet. GM has preliminary information on high-mileage 2007–2010 trucks and Cadillac CTS with idle surge and reduced power.
What it costs
The cheap outcome is a cleaned MAF sensor at $20–$60 or a throttle body cleaning and relearn at $80–$200. The common outcome is a vacuum leak repair at $50–$400 or a software update at $100–$200. The expensive outcome is a new electronic throttle body at $300–$700. A smoke test and a look at live data, $100–$180, usually tell leak from part before anything gets replaced.
Related codes
P0068 often comes with lean codes like P0171 when the cause is a leak, and with idle codes like P0507 (idle higher than expected). 11 complaints filed with NHTSA mention P0068, spread across 11 models, so no single car stands out; those are owner reports, not confirmed causes. If you’re not sure how to pull every code, see how to read check engine light codes.
What owners report to NHTSA
11 complaints filed with NHTSA mention P0068, 9 of them since 2015, across 11 different models. The component owners most often filed it under: engine.
Manufacturer service bulletins that name P0068
30 technical service bulletins and manufacturer communications filed with NHTSA mention P0068, from 13 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- HYUNDAI ELANTRA (2020), bulletin 10177135: Certain vehicles may experience an illuminated warning light due to Diagnostic Trouble Codes (DTC). Perform the ECU and TCU update, and, if necessary, replace the IVT (Intelligent Variable Transmission) to resolve this c…
- KIA FORTE (2019, 2020), bulletin 10179236: TECHNICAL SERVICE BULLETIN NU 2.0L MPI MIL ON DTC P010100 AND/OR P010600 AND/OR P006800 LOGIC IMPROVEMENT - This bulletin provides the procedure to improve the logic of the Engine Control Module (ECM) software and clean …
- MITSUBISHI LANCER EVOLUTION (2008, 2009, 2010, 2011), bulletin 10173900: In cold weather, false MIL illumination may occur on some affected vehicles during turbocharger operation below 3,000 rpm engine speed, due to improper intake air volume judgement parameter. DTCs P1235 (2008-2010 vehicle…
- FORD MUSTANG (2018, 2019), bulletin 10153934: Some 2018-2019 Mustang vehicles built on or before 17-Oct-2018 equipped with a 2.3L EcoBoost engine and operating in altitudes of 1067 meters (3500 feet) above sea level and higher may exhibit an illuminated MIL with onl…
- CADILLAC CTS (2007, 2008, 2009, 2010), bulletin 10126975: This PI was superseded to update model years and add information concerning idle surge, reduced engine power mode, and/or DTCs P0068, P0121, P1516, P2101, P2119, and/or P2176 that may be experienced on high mileage vehic…
- CHEVROLET AVALANCHE (2007, 2008, 2009, 2010), bulletin 10126975: This PI was superseded to update model years and add information concerning idle surge, reduced engine power mode, and/or DTCs P0068, P0121, P1516, P2101, P2119, and/or P2176 that may be experienced on high mileage vehic…
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
Can I drive with P0068?
Usually, yes, for short-term use. Many cars run normally with it. Some drop into reduced power or limit top speed, and a big air leak can make the idle surge or stall. If that happens, keep trips short and get it looked at soon.
Can a dirty throttle body cause P0068?
Yes. Carbon around the throttle plate changes how much air gets past it at a given opening, so the airflow reading stops matching the throttle angle. Kia's fix for P0068 on the 2019–2020 Forte 2.0L includes cleaning the throttle body along with a software update.
Can a vacuum leak cause P0068?
Yes, it is one of the most common causes. Air leaking in after the throttle raises manifold pressure at idle, and on MAF cars air leaking in after the sensor goes unmeasured. Either way the numbers stop agreeing.
Do I need a new throttle body for P0068?
Not usually. Check for leaks, clean the throttle body and do the relearn, and check for a software update first. Replace the throttle body only if it still reads wrong or its position sensors disagree.