Smog Certification upgraded engine?

Tiny
SALRAM19
  • MEMBER
  • 2002 CHEVROLET TAHOE
  • 5.3L
  • V8
  • 2WD
  • AUTOMATIC
  • 288,000 MILES
After building an upgraded engine how does it work with smog certification?
Wednesday, March 11th, 2026 AT 11:12 PM

7 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 55,535 POSTS
Hello,

The smog certification depends mainly on where the vehicle is registered. The engine and emissions system must be the same year or newer than the vehicle and all emissions equipment must remain. Can I ask which state you live in, also did you install a upgraded camshaft? This will determine if the check engine light says off. If the check engine light is on the car will not pass smog. Ken
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Thursday, March 12th, 2026 AT 9:10 AM
Tiny
SALRAM19
  • MEMBER
  • 4 POSTS
Yes, I’m in Upland, Cal, wanted to start building an engine for my 2002 Chevy Tahoe, before the one I have goes out.

And wanted to know what I can upgrade, that would not give me a hard time in passing smog test.

I saw your YouTube in rebuilding the lm7, and was wondering if I could do the same thing?
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Thursday, March 12th, 2026 AT 9:26 AM
Tiny
KEN L
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Yes, you can do the same thing but you will need a stock profile camshaft, if you get an aggressive camshaft the car with have a check engine light so it wont pass smog, all of the other upgrades are okay.
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Friday, March 13th, 2026 AT 9:22 AM
Tiny
SALRAM19
  • MEMBER
  • 4 POSTS
What camshaft do you recommend?
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Friday, March 13th, 2026 AT 11:13 AM
Tiny
KEN L
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  • 55,535 POSTS
If you go on Summitracing. Com the show the camshafts and which ones will pass smog or not.
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Saturday, March 14th, 2026 AT 10:57 AM
Tiny
SALRAM19
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Thank you
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Saturday, March 14th, 2026 AT 11:27 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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You are welcome, please use 2CarPros anytime.
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Saturday, March 14th, 2026 AT 11:37 AM

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