P2142 — Exhaust Gas Recirculation Throttle Control Circuit "A" High

P2142 — Exhaust Gas Recirculation Throttle Control Circuit "A" High. A fault in the exhaust gas recirculation (EGR) system. The car is usually drivable while you plan the repair. Typical causes: failed EGR valve or position sensor, faulty EGR solenoid or wiring, carbon buildup blocking the EGR valve or passages.

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK Generally safe to drive in the short term. Expect rough idle, pinging and higher emissions; on some cars the engine may derate. If the engine stalls or runs very rough, treat it as urgent.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm P2142 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the exhaust gas recirculation (EGR) system for damage, corrosion, chafing or poor contact.
  4. Subsystem check Command the EGR valve open/closed with a scanner and watch idle quality and position feedback.
  5. Subsystem check Remove and inspect the EGR valve and passages for carbon blockage before replacing parts.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2142 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2142 (parts and labor, USD, independent shop rates): Replace the EGR valve: $250–$650; Clean the EGR valve and passages: $120–$350; Repair vacuum lines or wiring: $80–$250. Overall, fixing P2142 usually costs between $80 and $650. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What is the most common cause of P2142?

The most common causes are: failed EGR valve or position sensor, faulty EGR solenoid or wiring, carbon buildup blocking the EGR valve or passages.

How do I diagnose P2142 myself?

Start with a scan: confirm P2142, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the exhaust gas recirculation (EGR) system, and verify the suspect component against live data before buying parts.

What are the symptoms of P2142?

Drivers most often notice: slight power loss, increased NOx emissions, rough idle or stalling at idle, Check Engine Light on.

Will P2142 clear itself?

Sometimes P2142 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

How much does it cost to fix P2142?

Replace the EGR valve — $250–$650; Clean the EGR valve and passages — $120–$350; Repair vacuum lines or wiring — $80–$250. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What does P2142 mean?

P2142 (Exhaust Gas Recirculation Throttle Control Circuit "A" High) is stored when self-diagnostics detect abnormal readings or behaviour of the exhaust gas recirculation (EGR) system. It belongs to the powertrain (engine/transmission) category.

The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores P2142 and switches on the warning light. Freeze frame data saved with the code shows the exact conditions — rpm, load, temperature, speed — at the moment the fault was detected, which is the best starting point for diagnosis.

Common symptoms of P2142

  • slight power loss
  • increased NOx emissions
  • rough idle or stalling at idle
  • Check Engine Light on
  • hesitation and pinging under load

What causes P2142?

  • carbon buildup blocking the EGR valve or passages
  • vacuum leaks in EGR control lines
  • ECM control circuit fault
  • faulty EGR solenoid or wiring

How to diagnose P2142

  1. Connect an OBD2 scanner, confirm P2142 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the exhaust gas recirculation (EGR) system for damage, corrosion, chafing or poor contact.
  4. Command the EGR valve open/closed with a scanner and watch idle quality and position feedback.
  5. Remove and inspect the EGR valve and passages for carbon blockage before replacing parts.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2142 does not return.

How to fix P2142

Start with the cheapest and most common causes before replacing expensive parts:

  • Replace the EGR valve — $250–$650
  • Clean the EGR valve and passages — $120–$350
  • Repair vacuum lines or wiring — $80–$250

How much does it cost to fix P2142?

Repair cost depends on which component actually failed. Typical scenarios for P2142 (parts and labor, USD, independent shop rates):

  • Replace the EGR valve: $250–$650
  • Clean the EGR valve and passages: $120–$350
  • Repair vacuum lines or wiring: $80–$250

Overall, fixing P2142 usually costs between $80 and $650. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P2142?

Generally safe to drive in the short term. Expect rough idle, pinging and higher emissions; on some cars the engine may derate. If the engine stalls or runs very rough, treat it as urgent.

Related OBD2 codes