Reduced engine power

2002 PONTIAC FIREBIRD
3.8L • MANUAL
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JTEMPLE105
  • MEMBER
  • 13 POSTS
Car is in limp mode I think will start every time runs very badl i can not accelerate help please code p1221 comes up i can erase it comes right back
Oct 4, 2026 at 9:58 AM
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KRAKENAUTO
  • ✓Experienced Mechanic
  • 97 POSTS
That's a Throttle position sensor code. It's part of your throttle body on that year. It'll go into limp mode for safety reasons.

First, check pins at the connector and the wires:
Locate the wiring connector plugged into the throttle body. Inspect the wires closely for chafing, tension, or pinching, and check the connector terminals for corrosion, moisture, or loose pins.

If the wiring, connector, and power supply check out fine, but live scan tool data shows continued sensor disagreement or the code immediately returns, the internal sensors have failed. I would recommend replacing the entire throttle body assembly.


If that all looks good otherwise, let us know so we can help you further.
Oct 4, 2026 at 12:04 PM
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