Aug 23, 2008
Which is the best 02 sensor too use Gm vs denso?

second question can a o2 sensor make it too rich at idle(BLM's) if its a shitty?
If you use race gas then the Denso 234-1001 is the one you want if you can find it. They've been discontinued but you can still find them around. I found one at the local Napa few months ago. If you really need a new Denso and can't find one in your area, PM me.

If you don't use race gas then the Bosch 12013 works well. Also discontinued (I think) but lots still floating around BOSCH Oxygen Sensor 12013 FOR Cadillac Chevrolet GMC Hummer Isuzu Jeep | eBay

The last AC Delco sensor I had went bad fast so I have trust issues with them.

Yes, a bad o2 can affect BLM's along with many other things. What are your o2 cross counts on your scanmaster doing?
I use the Denso. Stocked up at NAPA here a few months ago.
Flaky 02 sensors will cause all kinds of fueling issues as they report back to the ECM to set the fueling.
The reason why Im asking is because last year my blm's were 132 with the translator set at rich at idle. I think I had alot of vacuum leaks. This year I redid all vacuum related like plenum gasket/throttlebody seals/ housing gaskets/everything/ new both check valves and vacuum line/ new pcv valve(cleaned the kirban checkvalve hose/ billet vacuum block/egr gasket with ultra copper(rtv-make a gasket)replaced boost line with a 4mm tube & those push to connect compression fitting(nice n' clean at the rail). Even the vent breather from the gas tank a got gas air filter(where canister used to be hooked up). Cleaned valve cover breathers

When started couple of weeks ago for first time this year, I was so happy to see blm's where at 119. Then adjusted translator back to normal base switch for 3.5 LS1. Reset the chip, My blm's were 124/125 at idle. I was so happy, IAC was beauitful and holding after warming up at 14-19/TPS is perfect at 4.58WOT, and 44 at idle.
I wanted to raise the blm's closer to 128 so I switch the translator to lean at idle, now it's 131-132. I don't get it, why it went so high(like 6 points). Gas is still from before winter, I gotta fill it up. and replace my gas filter, it's been awhile.

My fuel pressure is at 44psi at idle with the line off, my TT chip is set for 17-18psi of boost on 94 octane(thats the highest pump gas here).The chip say's start at fuel pressure 43psi(+/-) after that. I figured 43psi is 17/44psi line off would be 18pounds of boost. I think.

Thinking of switching translator back to base switch & problably drop 1 psi of fuel to 43psi vacuum line off.

Nothing is wrong with my injectors/seals, pump. Its all been replaced new not long ago.

My CC counts weren't moving when translator was set at lean at idle. CC counts were moving steady when translator was set at base switch( when my blm's were 124-125
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I went with the denso sensor because somebody told me they dont mess up often like the ac delco ones.
How does the tank vent work with the small filter? Gas fumes? I was gonna do something similar, but raise the height with more tubing first. Mebbie make it loop up just under the top of the fender
We have mountains here in AZ. and I am concerned about long down hill runs and if I have to brake hard due to the "flatlanders" driving slow due to fears of "falling off of the mountain."
We have lots of steep grades here with no "ARMCO."
The previous owner removed the vapor cannister and CAPPED THE VENT!
Is there another vent in the rear, like in the older cars, behind the rear seat? Or is this the only vent? If so, then the cap is as stupid as other things I have found!
Also, the big vacuum ball was in the trunk, where is the stock location, and where should it connect? My car has cruise control. Should I "T" it off of that? Or into the HVAC system? They both have separate vacuum connections. Thanks for any info!
The last owner had FOUR different shops work on it after the "new motor" was installed, none of them could even make it run! I am going thru every circuit, hose, nut, and bolt, before I try to drive it!
The Vacuum ball( Vacuum storage ball). its suppose to be located front drivers-side under the car, I think it mounts on the side fender. Thats the storage ball for our HVAC(heat/AC)thats where the extra air just sits.

I'm very happy with the filter, doesnt really smell gas like it did before. Thats a breather for the gas tank, And also the buick vacuum diagram includes it as part of vacuum system. It's a vent breather filter, I dont know if you can just plug it. I dont think so. I think it would create pressure, but not sure.

Here's where I got the filter, It's the correct filter for gas vents/crackcases etc. It wont smell like before, it's like $50. They sell other kinds too like inline kinda stuff. I just got the filter. You even can ask them, but thats what it is.

In the menu on top/ Go to Motorsports/ then on the left side go to fuel delivery systems/then on the left side -Filters.
I got the 3/8" clamp on one. fits great, just got snug the clamp down.
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Anybody got a pic of where the vacuum ball mounts?
Thx for the vent info!
Yes. That two way check valve from lets say from EGR vacuum port. Yeah use a line from port too one way checkvalve, then another line. Then connect it too the larger port on the two way check valve. The other side of the two way check valve up straight port goes to HVAC in the car. The other port that points sideways towards driverside fender goes to vacuum ball, if u have cruise control T it so one goes to ball and other goes to cruise