99 Tahoe advice

[Stinky_Hooker]

There were no Pcodes. Its was low effeciency through caty convertors which he said was waaay before I started having problems, a fuel level sensor (which I knew, cause my fuel gauge doesnt work) thats it. I was hoping for a trans code but nothing.

I only took it to him cause he is really honest and wanted to see A: if there were trans codes and B: if it may have been an engine issue before concluding it was the tranny, which it obviously is. He gave me the # to a tranny guy he trusts and Im going to call him this afternoon when I get off work (left the number at home). If they work tommorrow I may run it by today, if not Monday. I been driving it in 3rd only 40 MPH or so to keep the shudder down to hopefully not cause any damage. I only drive 5 miles to work each way. No driving it otherwise.

[THEFERMANATOR]

Originally Posted by Stinky_Hooker

There were no Pcodes. Its was low effeciency through caty convertors which he said was waaay before I started having problems, a fuel level sensor (which I knew, cause my fuel gauge doesnt work) thats it. I was hoping for a trans code but nothing.

I only took it to him cause he is really honest and wanted to see A: if there were trans codes and B: if it may have been an engine issue before concluding it was the tranny, which it obviously is. He gave me the # to a tranny guy he trusts and Im going to call him this afternoon when I get off work (left the number at home). If they work tommorrow I may run it by today, if not Monday. I been driving it in 3rd only 40 MPH or so to keep the shudder down to hopefully not cause any damage. I only drive 5 miles to work each way. No driving it otherwise.

The 2 conditions you describe would have both been a P code. The ECM reads out trouble codes for the powertrain(engine/trans) as P or powertrain codes. The cat efficiency code can EASLIY cause the problem you describe from it as I have SEEN it happen on 99 5.7's. This is why I said we needed to know what the P codes were to go off of, and NOT to trust the diagnostic trouble codes given for this engine as most of teh time they can lead you on a wild goose chase if your not familiar with the system. As for seals on teh input shaft, I find it HIGHLY unlikely the teflon seals have gone bad unless somebody pulled the trans apart and put it back together dry with a sledge hammer. Since the late 80's GM has used teflon sealing rings and they are VERY resiliant and hardly ever need changing even during a rebuild.

I haven't ever used one of these, but I have read good things about this for the P1870 repair for alot less money. Supposedly it will work better in valve bodies that are severely worn that the tRANSGO kit won't fix.
http://www.teckpak-fitzall.com/spgm.cfm?id=A74741Q

[Stinky_Hooker]

Well crap, to eliminate the cats starting to get clogged what do I do short of replacing them for alot of $$.

[Stinky_Hooker]

Ferm I miss understood what you were asking about the p codes.


I just picked it up from the shop and I have a list of the codes Standby till I get home I'm on my phone.

[Stinky_Hooker]

Here ferm

[THEFERMANATOR]

From what I see I would find a new shop to go to. Your truck only has 2 cats, NOT 3. Bad vibration from the torque converter? How did he come to that conclusion? I hate seeing receipts like these as most of the time it means they didn't really check anything. The P0420 and P0430 both being in there concerns me the most. I would check the fuel pressure on it to make sure it is up to par. If it was one or the other I could see a bad cat, but both at the same time normally means a fuel delivery problem or an injector issue. How does it start cold? How does it start hot? Do you have problems restarting it hot after it sits for about 10 minutes? To remove the cats there are a few different ways of doing it, but all of them are pretty illegal and the EPA is out for blood here lately over emissions equipment tampering. PM me for ways to disable them for "testing" purposes if you want. Also the P0440 could be the cause of your P0420 and P0430 codes. If the evap purge solonoid is stuck on, then it can cause a rich fuel condition causing it to surge or buck as well as throw cat converter efficiency codes.

[Stinky_Hooker]

I was assuming the third cat was the 3 of 4 oxygen sensors?


I have a guy that will cut my converters off and weld them straight. I had it done on a 2001 s 10. It cause the light to come on but what will it do to my tahoe will it run right? Hell for that matter I can straight pipe it...what will happen?
Would that be what you would do next?


Also I think he came up with the vibration from the torque converter based on driving it and I told him I replaced it.

Thoughts?

[THEFERMANATOR]

This is a 350 or 5.7L engine with a distributor correct? I have never seen one, but I have heard some 99's came with the 4.8 and 5.3L engine. I just want to make sure. As for your O2 sensor, there is one after each manifold, and one after each cat. If you straight pipe it it will go into engine protection mode and limit the timing WAY back. I do NOT reccomend doing it as CAT's aren't that expensive if you get aftermarket MAGNAFLOW universal ones(last ones I bought were $65 each). With the P0440 code, there is a GOOD chance your WHOLE problem is nothing more than a stuck open evaportive emissions valve venting fuel vapors to the engine and fattening out the mixture. This will cause it to be off on the timing tables and show both cats as having poor efficiency.

[Stinky_Hooker]

Well Ferm, I thought I would update you. Took it to the transmission guy and dropped it off two weeks ago, (I got it back last tuesday). On the way over there to drop it off it started getting real bad.

He called me the day after I dropped it of and said it was definately loosing pressure and they found a good bit of dust from what he thought was the 3rd and 4th gear clutches wearing out and thats what I was feeling on my way over. Anyways, he offered to go into it and try a few different things to figure wear the pressure was being lost. It may have been overkill but with my several months of frustration and missing over a month of hunting I told him to give me a price and just rebuild the damn thing!!

Anyways, long story short and $1900 later she's running like a top. I felt good about the decision because of the piece of mind I FINALLY have, the motor only has 40K on it and he gave me a 12 month/12K mile warranty on the tranny.

The truck might be an old 99' but I love her and she's worth it to me...and PAID for.

[Stinky_Hooker]

Also, does anyone have an extra grill emblem laying around or where to get one reasonable. Mine disappeared!