After building an upgraded engine how does it work with smog certification?
Mar 11, 2026 at 11:12 PM
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STRAILER
CERTIFIED EXPERT
53,854 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
Mar 12, 2026 at 9:10 AM
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 ?
Mar 12, 2026 at 9:26 AM
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STRAILER
CERTIFIED EXPERT
53,854 POSTS
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.
Mar 13, 2026 at 9:22 AM
SALRAM19
MEMBER
4 POSTS
what camshaft do you recommend?
Mar 13, 2026 at 11:13 AM
STRAILER
CERTIFIED EXPERT
53,854 POSTS
If you go on Summitracing.com the show the camshafts and which ones will pass smog or not.