That Theory sounds right to me. My MAF values are a little higher than normal I do know that (While driving) but not that much higer mabee by 20 GPS or so. But, Like I said before, I am sure once I but the blower on my car and get it tuned, most of these issues will be resolved.

 

95 Silver TA, what do your BLMs read in all the cells? mainly cells 02, 06, 10 and 14? by just decreasing your MAF values...that will fix low BLMs. also i got a real bad split in my BLMs when one of my O2 sensors bit the dust so if you havent replaced yours yet then id start there first.

 

I am not to sure about all the cells but I do remember seeing 5 and 6 and sometimes 11s. I will start paying more attention to see if they are the same as yours and I do plan to buy some new 02 sensors soon too cuz My old ones have 120K on em.

Thanks for the advise..Its much appreciated!
Claude

 

Intresting theory, however it doesnt explain why it happens to me since I dont have a MAF. Besides while the headers do increase airflow the PCM will see that and add more fuel accordingly. That is the whole point in having a MAF, to measure airflow so the PCM can determine how much fuel it needs. I dont understand what you mean by "weird numbers"

 

I've been around cars for decades, but I'm new to the LT1 Edit list. I was reading about the MAF values being altered from the manufacturer specifications. Apparantly, if the G/PS reading on the MAF is affected out of spec due to modifications to the intake, exhaust, cam, head, etc... it will alter the reading of the MAF out of spec. While the data from the MAF is true, it's values will not comply with the matrix of the PCM. So the MAF values must be raised or dropped to comply with the PCM... which will result in BLMs reading 128 (or as close as possible). BLMs meaning your long term fuel trim.

 

Any updated information or new thoughts on this? I'm still having issues.

Rob
95Z28

 

I would still consider myself new to edit. But to follow up on the MAF, I've been reading that any adjustment to the MAF may recalibrate itself into a norm operation. I really haven't tinkered with the MAF but I can confirm that Longtubes affect the O2s. If .920 is norm on and O2 with stock manifolds, that would equate to .870 on Longtubes. So, if the programming is raised to bring the O2s on longtubes up to .920, then they would be running very rich... possible foul out? O2s work best when they are hot, that's why they are typically close to the exhaust port or collector. However, longtubes have the collector far away which will affect the temps of the O2s.

TTT for ya.

 

well I've solved my problem with new pre-cat 02's, I suspect mine were original which are good for 50k miles from what the autoparts stated. Car runs like a beast again. This time I also soldered my 02 extensions vs butt connectors on the stock 02's. I probably could use a dynotune since this car breathes so open now compared to stock. I didn't realize opening these LT1's up with CAI, longtubes & Borla would make it run rich but be what it may it works now, see how long it lasts. Wish I could have found AC Delco's vs Bosch from what I've read but it's all I could get in time.

 

Andyone ever figure anything out? I seem to have the same problem. Sensors that after about a month and a half start to go lazy and the car runing with low 108 blms.

Hey ryaskovic, did your timing trick work or not?? Just wondering.

Jason

 

Nope, nothing new here. This last set of O2s that I installed do seem to be lasting a bit longer but I'm not counting my chickens just yet. Overall the car is having issues that I haven't gotten to the bottom of. Something's just not right and I haven't been able to figure out what.

Rob
95Z28