The other day I ran a scan to check on things and an overboost code came up. I have no real mods yet installed on my truck besides a BD fuel pump. How could I overboost? Earlier that day I did have the truck in 4low and I went up a muddy hill kind of on it just to make it up. Could that have been it? -

Renteria1217's Sig:

1998.5 Dodge Ram 2500 5.9L 24v Cummins QC/SB. Replaced VP44 with rebuilt, Inline BD fuel pump mounted just outside gas tank ran with stock lift pump. No other mods as of yet.

Anyone? -

I know you said you have not add ons but we had an over boost with a defective edge EZ took a couple of day to find out after testing everything. Probable a faulty Map sensor. Ed -

Was it the MAP sensor on yours or was it the chip? If the MAP sensor was bad, wouldn't that come up as a different code for itself? -

You would get an underboost or MAP sensor voltage too low code -

wildbill's Sig:

06 QCSB Mineral Gray: Stock W/ a Mag Hytec Trans Pan, ATS 5 Converter, CAT Delete, Aeroturbine Muffler, and Gauges=Oil Pressure, Trans Temp, Boost, and EGT
Parked Until Repaired

Current Ride: 1982 C10 Chevrolet Scottsdale 4x4, 6.2 Diesel, 4 Spd Muncie (Replaced Chrysler POS), Super Swampers, 2" Lift, 255,000 Mi. Top Speed 55 MPH!!!

Bad MAP sensors can produce both codes of too high of boost and too low.

Dave -

Fishin2Deep4U's Sig:

'02 Dodge CTD - Mostly stock.

Vulcan Performance

Sales - Dave Conrad

Direct line 503-970-6712


Fight N Fish Guide Service

I cleared the code after the scan. So if it continues to come back, should I change my MAP sensor then? -

Before u go and get a map sensor, I would hook up a mechanical gauge and c if ur getting 25-30 psi. Also, the waste gate tends 2 seize. this happened on mine and boost maxes out at about 40 psi but still didn't generate a "too high boost code" -

I thought it was at 22 psi that you get a boost code. How could the turbo push 40 psi on a pretty much stock truck? I didn't know that was possible. With no mods is it possible to overboost to the point of engine damage? -

[quote=Renteria1217;221525]I thought it was at 22 psi that you get a boost code. How could the turbo push 40 psi on a pretty much stock truck? I didn't know that was possible. With no mods is it possible to overboost to the point of engine damage?[/QUOTE

ur boost would certainly go higher if ur waste gate was seized. How high depends on what fuel amount is being injected. In my case, I have the edge juice with power level 6. If in ur case, if u r stock, u wont reach that value. With no mods, I hardly think u would reach 30 psi with waste gate seized. -

I see alot of people that do block off the waste gate on purpose. How does that make more boost exactly? Is that recomended? Also, being with no mods I can't really get enough boost to do any damage to the truck from what I understand, but if I throw the overboost code what does it do to my truck? I've read that it defuels. Does it defuel at that moment or how does that work? I've also seen "limp mode", what is this exactly? -

I recall disconnecting the waste gate actuator hose and plugging the compressor port and all the stock turbo could provide is 35 psi of boost which is still a safe margin 4 that engine as long as ur egt's stay within the limit. in my case, I dont tow, so these high boost levels r only 4 a few secs. The waste gate opens an exhaust port in the turbine housing, bypassing the turbine, slowing the turbo down, hence governing the max boost level. not really recommended. u should have fuel pressure, boost and egt gauges. this way, just at a glance, u will know how ur engine is doing. I never seen the overboost and limp mode on my truck so I cant tell u much bout that. limp mode is a default setting that will get u 2 the garage, I presume in lean and gutless fueling state! -

Beleive it or not but low batteries and faulty grounds can cause that code as well. Been there done that. -

Wyatt Earp's Sig:

Wyatt Earp
2002 Dodge CTD, 6spd, 4x4 LWB, QC, SLT, 354 gears, 150 HP sticks, EDGE Comp, Smarty Box, FASS 150.150, FP, Boost, Pyro on A-Pillar, Ring MIA, AFE STG 2 w/sock, Custom fuel heater, 4" MBRP SS Cool Duals w/ 5" tips, Trailer brakes, Custom lights, Carrier springs, DSS, Lukes Links, 285 Toyo M/T's, Sony deck, changer, MD player, Rockford speakers

Yeah I really need to get guages. I'm actually just going to go with a monitor so I don't have to have so many guages. That kinda stuff was going to be the first things I did to this truck, but 4 freakin days after I bought it, the vp went out. I dropped about $1700 right off. That was just parts, I did the labor. It's crazy how expensive these things can be. So back to the overboost code...I didn't know batteries could play in on this. My batteries are brand new, but I know the grounds aren't done the best. I didn't have the right connectors when I put on the new batteries so I had to use what was laying around. The ground on one of the batteries isn't the best. Say it did come loose and I had a bad connection, could that throw an overboost code? Even if it's just one of the batteries, or would it have to be both? -

Yes. First place to check for loose cables is the air intake horn (intake manifold). Follow those down to the battery tray on drivers side and inspect carefully. Check them all, clean all the terminal posts and get a good seal with a cleaned post and you will get rid of the code - if that was the problem. -