Potential trouble, heading to a dealer next thus. Appreciate any advice

[Ob1Cnob]

I recently bought a 2002 GMC duramax. The only mod it had was a K & N air intake. It has only 69,000 mile on it. The entire unit from chasis to engine to interior is spotless. So my guess is that it was not used much. Not even one oil leak. Upon recieving my truck I had the following done: Oil and filter change, cleaned K & N, changed both differetntials, fuel filter change, transmission pan and screw on filter and fluid change, transfer case change, new shocks.
I am new to diesels, but to me the truck ran "as new". After reading much on line I decided to install a full 4" exhaust system from Summit. It is basically a stright through pipe with a small glass pack. I must say my truck was one of the few that had a catalytic converter.
My Questions:
1 - After installing the exhaust, I immediately noticed a VERY strong pungent smell of diesel fuel. I assumed it was because the catylitic converter was no longer on the truck. I can't even enjoy a drive through meal without blowing out my occupants. Could putting my cat back on solve this or was it just masking a problem?
2 - My next mod was to install a program. I tried the predator, but it would not recognize my trucks "program" for lack of better terms. So I bought a hypertech and went for stage 3. Loved the additional power, but now I noticed white smoke at idle. SO, I went back to my factory program. Now though, I still get white smoke at idle once in a while. Maybe after flooring it and loading up the truck. The white smoke is not continuous. Any ideas?
There is no knock as of now, but I'd rather be preventitive. I have made an appointment to have my truck diagnosed. It still falls under GM's warrentee, 7-100,000. Any idea if:
- They will fault me for removing the catylitic converter and blame that for my problems? Should I put it back on before going to service?
- If my injectors are begining to die, would their diagnostics pick it up no problem?
Thanks in advance,
Steve
P.S. No diesel smell in oil, and for now paper towel test seems OK.

[Mark Rinker]

Sounds like early signs of injector hanging up. Dealer would probably see it in a high return rate. My 280K mile 2002 recently started smoking at idle, and is on its second set of injectors - the first set replaced at 170K.

I might get harpooned for suggesting this, but over the last month, I have added 1 quart of ATF (the cheapest brand I could find) with each ~30 gallon fillup.

As of this week, the smoking at idle has subsided...

[Luis]

I would put the `cat' back on so they don't deny your claim for any reason! Why risk it...The extended warranty is 7 years from the In Service Date (ISD) date OR 200K...Ask your dealer or any GM dealer for this date as a future refference...In Service Date is the date the vehicle was FIRST SOLD to whom-ever...I just went thru an ordeal to get my injectors repalcement covered when I was two months past the ISD with 119k...Unless your a gambler its worth the extra effort to put back to original...I was asked about any `mods' and I could honestly say I never had any...then I was asked about fuel additives...no....then I was asked about fuel filter brands...I had an AC fuel filter on the truck to back it up...I would take this opportunity and do yourself a favor, [for now and the future] buy a FUMOTO valve and order an OIL Analsys Kit from AMSOIL (search this sites vendors). When you recieve both, change your oil, take a sample with the kit and install the new FOMOTO valve. This valve will allow you to pull future oil samples without draining all 10 quarts and/or making a mess...it works well! The results from the oil sample will give you a true baseline of whats going on in your engine...
Good luck and prayer allways works too!