I have a 03 blazer 4.3 4D 4x4 Auto with 65,000, I just installed exhaust, throttle body spacer and a K&N FIPK. After everything was installed I started the engine and it started fine and idled fine but when you put it into any gear it idles rough and the oil pressure gauge twitches, not a lot but a little and it did not do that before the upgrades were installed. I also scanned for any codes that it may throw but it passes all tests does anyone know what it could be or put me on somewhat a path to start checking with? thanks ya'll

 

How much does it twitch? What does it center around when idling? How about when higher up in the RPM range?

If you never dip below 10psi, you have nothing to worry about. Some sending units are more sensitive than others. I wouldn't worry about it so long as you have sufficient pressure.

 

Kyle, I think the rough idle he spoke of might be the cause of the gauge twitching, but I can't see what he did that might have caused it other than maybe the tbs. Any ideas on that?

 

Make sure all your vacuum lines are connected properly, and that none leak...

 

I'll check all of the lines today and see if I maybe knocked one loose while I was installing of the parts, will let ya'll know what I find (if I find anything) Thanks

 

ok I checked all of the vacum lines and they all look good and on tight, the oil psi is at about 40 and goes to about 60 when on the gas. Someone told me that when you change the amount of air coming into the engine you have to reprogram the computer. I dont think this is right that it what the sensors are for ..... right???

 

Sometimes the sensors need time to adjust... At least they did on my old car...

Adding new exhaust didn't change anything on mine...

Maybe check for leaks or a restriction where the TB spacer is...

Or if it's not too difficult or time consuming, try it without the spacer...

 

I think I might do that, I will take the tbs off and see if it still idles rough and if it does i'll take the FIPK off and see which one if it is one of them is causing it .... thanks for the ideas

 

You could try unplugging the battery for 10 - 15 minutes, and let the computer re-learn from scratch...

 

Michael, the part about your oil pressure just took a turn. Your first post said the gauge 'twitches'. What you just described is not a twitch, it is the normal fluctuation of pressure between idle and accelerating. This is perfectly normal.