stock MAF question, also code 45 rich 02 code


wana steal it? meet mr9mm
Staff member
Nov 24, 2001
Got the sage green car driving today, been sitting for awhile, started it every month, just couldnt drive it.... had a bad tranny...
At idle stock maf was reading 03 both screens are removed
Installed other stock maf, now reading 05 at idle with one screen. < runs alot better with it.

I would assume, that with both screens removed it would read higher, just wondering... Car would hunt and change rpms with the maf with both screens removed. Will install 1 screen and see how it does...

So i changed chips, spark plugs and installed a brand new heated 02 sensor.
Get this, turn down fuel pressure to 40 psi vac off, 30 with hose on, has msd 50s and 26° race chip NOT a TT chip.... cant wait for the new TT chip...

Anyway, fuel at 40psi hose off, reset ecm for a fresh breath of air... start car and let it idle.
blms at 105 at idle... can you say rich bitch?
Now it threw a code 45 and i didnt have it running but for 5 minutes just to bring the temps back up..
Motor was hot when i did plugs and 02 sensor..

Car doesnt smell rich at all, just cant believe code 45 and low blms that quick.
18" of vacuum...
Cant wait for to get the boost up and dial this sucker in...

Chip program making it so rich?
I tried 3 different "brands"

Or was it the maf with 2 screens removed?

It got too dark out, and i didnt want to piss the neighbors off anymore, single shot tis a lil loud :eek:

2 separate issues of was it the maf with 2 screens removed?
None are programmed for missing maf screens.

Trouble Code 45 indicates that the O2 sensor is showing a persistently low exhaust oxygen content (rich), despite the efforts of the ECM to decrease injector on-time (thus decreasing fuel delivered). Integrator and BLM numbers may indicate < 128 by a substantial margin.

The conditions for setting this code are:

no Code 34 or Code 35 (MAF error) present, and
the O2 sensor voltage remains above 752 mV, and
the ECM is in Closed Loop control, and
throttle position is < 2 percent or > 20 percent, and
the above conditions exist for more than 20 seconds.

Typical causes for this code include:

1) O2 sensor defective or contaminated (if incorrect RTV sealant or too much RTV is used, this may happen)
2) Leaking fuel injectors
3) Fuel pressure too high
4) EMI interference from poor plug wires
5) Evaporative Emission system defect
6) TPS and/or EGR problem
7) MAF sensor reading higher airflow than is actually present

Had to be the maf... i guess... got too dark!
1 brand new 02,.. then again the other one didnt throw a code BLM was 105 with both.
2 holds 30psi for 30 minutes
3 set at 40psi
4 five are magnacores right at 3.3K ohms one is a good belden, found 1 magnacore was bad during the spark plug swapage.
Msd's are going to be ordered this week.
5 no hose leading to that and no evap setup!
6 tps is .42 and 4.6 wot, egr is GM, no hose leading to that either....
cant wait for my TT chip
7 was only 03 with 2 screens removed... that has to be it, along with other factory stuff taken off and chips not programmed for it????

BW :biggrin:
I have 50's, and Ive had to be very creative in my quest to balance my BLM's out. They have wanted to peg rich since day blm's locked in at 90 rich. I created some intentional leaks after the MAF to get my idle BLMs up, and ran my translator 10% lean at idle...I did alot of things, but nothing made as much of a difference as the new updated translator chip Mike Licht sent me. I used to have to bring my BLM offset down to 1 just to get it in a decent range. Now its at the extender chips default of 8, and my idle blm's are 115, and 128-130 at cruise. Its better than its ever been, and since the blm's arent pegged out, I know the computer is still adjusting and is fine.
But get this- I have a code 44 and a code 45 in my scanmaster! I'm lean AND rich! My damn car is going to give me a stroke. :mad:
Well i blew both head gaskets, the felpro 1007s lifted... damn lock wires...
Gotta make another post.
So that was the reason for your issues? Headgaskets? Or is this on another car? Or did you take it out, get into boost and then blow the HG's?
If your syptoms were caused by the blown HG, then Im starting to get worried. My car has the same issues. Low BLMs since day 1. Car had major vacuum leaks for god knows how long, and I have no idea how bad the previous owner beat on it while it had a vacuum leak so bad it was losing 5" of vacuum. :eek: It was from bad o-rings on old stock injectors. I used to get up to 14 degrees of KR at only 12psi cause it was so bad. Ever since I bought the car, I get a little steam out of the exhaust, but it really doesnt drink antifreeze. The coolant overflow has gone down quite a bit, but I figured its easy to evaporate that much over the course of a few months. Its not like the overflow tank is sealed. Theres no oil in the water and water/oil.. Could be cam gear? I have 150psi cold cylinder pressure. Bad gas mileage...God I hope i dont have blown HG's.
Never mind just thinking outloud..
no, issues were rich idle... head gaskets were fine for at least 600 feet.

probably from the chipssss i tried and finally went with reds 107, i knew it was matched for 50s on a 3.8.. but my boost wasnt set right. only got to 16psi and i seemed to finally blow my first set of head gaskets on a turbo buick.... EVER. I did a good job, set me back a few hours this evening, i had to call some buds over and tear it apart so the cyls wouldnt rust...

I did something wrong putting this motor together, and i think it was using these heads and gaskets...this motor was fine before with graphite gaskets.. :eek:
At least i got to drive it..

Removing the screens from the MAF may cause problems, and offers very little in return. Some of the chips burners have a chip which will help. The screens are there to make the MAF read accurately at low flow- they are actually flow straighteners, not "screens". If they are left out, the MAF can read low or high. If your MAF is reading high, that could cause the Code.
Ormand said:
Removing the screens from the MAF may cause problems, and offers very little in return. Some of the chips burners have a chip which will help. The screens are there to make the MAF read accurately at low flow- they are actually flow straighteners, not "screens". If they are left out, the MAF can read low or high. If your MAF is reading high, that could cause the Code.
The screen is there to create a uniform turbulence throughout the tube. Without the screen, flow is laminar. The speed and volume of air is greater at the center of the tube than the walls. If its laminar, the strain gauge in the MAF cannot give the computer a proper idea what the true volume of air is, because the strain gauge may be in a dead spot, or a high flow area. Just like the screen on a water faucet, it makes the speed and volume of the moving water much more equal no matter where in the tube you are, so that the strain gauge placement is no longer that important. Losing the screen can cause A/F problems, but usually not so severe that you blow your motor at 16psi. About 7 years ago, we made a little strain gauge calibration system for some customer. We used fixturing for the strain gauges, and made a reciprocating assembly mounted to a Sony Robokid robot that would rub on the face of the strain gauge, along with a very fine rubbing compound. A couple microns would be removed from the thickness, and the calibration of the gauge would change. Anyway, I was surprised to see a strain gauge in the stock MAF when I was looking at it a couple weeks ago. The gauge looks like someone put pressure on it and stretched it, cause it's not totally flat anymore. Its like a loose piece of paper that wobbles around. Using everything I learned years ago, I can say that my MAF is trashed. If a strain gauge has become loose from stretching, or has been worn down at all, the calibration is completely altered. They use these things in precision scales and all kinds of stuff. Sorry for getting off the subject :eek: