Originally Posted by 89gt-stanger
Toby- To be fair, I am running a TS tune through an SCT tuner. I have been getting a P219a code saying that bank 1 has bad a/f. I do have cat delets though, so I kind of expected to have some issues with cel's anyways. The car runs great otherwise! Tell tim to PM me back so I can get the car in to have the gears looked at  |
That is more then likely a bad oxygen sensor. It seems to be a very common problem with these new 5.0's especially ones with headers. I am yet to come up with an opinion as to why this happens. Although I am leaning towards a quality problem with the sensors in general as i have seen brand new ford sensors bad right out of the box!
The biggest problem i have with any mail order tune even the ''street tune'' ones, is when you are out getting that log to send to the tuner, if something happens, and it goes lean or begins to detonate and the driver does not recognize either one. guess what happens? the motor goes boom... Honestly yes a street tune with the vehicle moving and air flowing across the engine and filter, you will get a more accurate tune. thus the reason we tune on the dyno then go on a quick test drive to verify everything is fine with driveabilty. As stated before, we are yet "knocks on wood" to have a single issue with this method on any vehicle we tune. But a full on dyno tune can be just as accurate if the tuner knows what he is doing. I have seen some tuners push the limits so hard in the name of 5-10 hp that devistation results. We do not push that bar at all. All of our tunes are extremely safe to be driven in any conditions without the worry of bad results. Yes we like to provide a quality product and quality tune, but we do not want to risk anything. There have been multiple cases where we get guys in that have a mail order tune and in some cases they were ''street'' tunes. We make a few dyno pulls, sean works his magic, and ends up with 10+ peak hp and lots under the curve.
There is a huge misconception about afr. Most dyno tuners aim for 12.8 n/a and 11.8 boosted. Most mail order tuners do their testing at 12.2 and 11.2 so that there is room for error as not every car is the same. Engine spec's being as little as .001 off on anything can be the difference in lasting or it blowing and can vary how the combustion takes advantage of that air and fuel coming in. I have personally built a huge amount of engines 100+. Everything from 1500+ hp race motors, to 200 hp bone stock fox motors and everything in between. Building engines, setting clearances, that is my true passion! How the shortblock is put together, can affect the end hp by as much as 100 rwhp! Afr is about 15% of the power an engine makes, timing is where you really see a difference in power. 1 degree of timing can be as much as 20-30 hp on some engines, where as 12.8 afr will be almost identical hp as 12.2 or 13.4. I have seen cars make more hp just by letting the engine cool for 10 more minutes before making a pull then i have by seeing afr change by a couple hundreths. So long as your afr is within reason of 12.8 ish na, you are fine. (ie: 13.2 and richer) Now naturally if you are running 13.9 and higher at wot, damage can occur, and the same can be said if you are too rich, washing the rings and bearing out will happen if you are too rich and the fuel begins to puddle and is not atomizing properly.
Sorry for the long post, but this is just a pin head of what goes on with tuning and the results of different settings.