quickWS6

I Atapped my car today, at cold idle the Ltrims are both 0%, but I get some backfiring if I let it go below 1000 RPM. I'm having lots of misfires on #6 too, I don't think it is firing at all. Once it warms up though Bank 2 goes to +25%. 02 sensor B1S1 was around .850-.950 volts. B2S1 was around .300-.400 volts. At times the B1S1 02 went as low as .050 volts, and stayed under .100, then jumped back up to the .850 range. The manifold vacuum was in the 4 range also. I replaced the 02s and the driver side one looks different then the stock one. I'm getting the TPS code and P0306 also, anyone know what that is? The intake is seated well and all the vacuum lines are plugged correctly, as far as I know. There was a hole that didn't have a line on it, and I put a rubber boot over it. I could not find another line that could go to it. It is the bottom hole on the block that is on the drivers side of the intake. It has a wire that connects to the front, and two lines that look like vacuum hoses go to them on the back. I just changed the passenger side header gasket, also. Could it be the wires that connect the 02 sensors to the wiring harness? Thanks a lot for any help!

I don't have my HVAC system anymore, do I even need any of the small rubber vacuum lines on the back of the intake? Can I just put a grommet over the holes? Thanks!

Bink

Double check your O2 sensor connections. It seems like you may have them reversed_ Im assuming it's possible with an F-body with headers.I have a Y-body with longtubes and it's easy to cross them. I know because I did it!!!Hope this helps some.Good luck!
joel(Bink)

quickWS6

I just went back through the log, the B2S1 02 jumped up to .700 at times also, but stayed around .350 more than anything else. B1S1 jumped around a good bit, but it was drastic changes.

The B1S2 and B2S2 02s were around .450 the entire time, I'm guessing these are the rear 02s, which I don't have connected anymore. Any ideas?

quickWS6

Also, I have a Pace LS6 MAF, could that be affecting it?

I'm assuming this is happening once my car goes into closed loop. And how much are the 02 sensor readings supposed to change? I'm not getting any codes for the 02s, but they seem to stay around the same number a good bit. Thanks!

quickWS6

I took my MAF off to clean it, and I noticed one of the very small wires was bent. I ordered a SLP MAF to replace it.

Here is my plan:

Buy new exhaust manifold gasket (one has RTV on it)
Replace upper 02 wiring on passenger side.
Buy new coil for #6.

I'll see what that does and check on the 02s from there.

quickWS6

ttt

Tom99SS

iTrader: (2)

Before you buy a coil for #6, check the plug and wire first. Plugs have been known to close their gap when installing (hitting them accidentily against something while installing them). Also, see if wire is on tight at coil and plug. Also check ohms of wire.

-Tom

quickWS6

Could all this be caused by a small vacuum leak in the HVAC hoses? My Metco breather has never set completely right either. I am going to try and go back to the stock oil filler neck and find the hole in the vacuum hose.

CAT3

iTrader: (9)

When your giving the readings on the B1 & B2 S1's are you giving the idle readings? From your post that the way it sounds, which wont help any. The b1 & b2 are good for WOT and cold only unless I am mistaken! They will bounce all around when idle and part throttle. But when the WOT comes, it will raise (or lower in some cases) and settle to around .800-.9xx somewhere around there. Check that out.
And the rears are right, .450 for simms. Mine actually read .450/.455mV

Good-luck

Charlie.

quickWS6

I was wondering if there was a problem because the B2S1 wasn't jumping around enough. It stayed at .350 almost the entire time I was logging. I haven't taken it down the road because it backfires a lot and is running 25% on Bank 2.

JWRENCH

Sounds like the maf and all is fine. You might be getting extra air sucked in somewhere on the passenger side. I'd check the intake and header gaskets really close. Also make sure there aren't white spots on your passenger side 02. If so that rtv probably poisoned it.

Navy David SS

iTrader: (13)

No. 1 - your O2's are for WOT only. Period. Has nothing to do with idle.

Ltrim on the other hand are for idle. Actually I had the same problem. I changed everything. Check for the smallest of vacuum leaks. Any vacuum leak, header leak, will effect the Ltrim. Ended up taking it to the dealership to put on their computer. Injectors, compression, leak-down was good. Solution: the intake was loose. Tightened it, Ltrims are back to normal. If haven't check the intake, go to www.ls1howto.com - intake swap - for tq specs.

You are right not to run it when the Ltrims are at +25 on one side and 0 on the other. This is warning you of a lean condition.

Do you have an MAFT? If so, when you move the base does the Ltrim move?

Sparky

Fix your misfire first. If you've got a miss on cyl 6, you're dumping raw gas into the exhaust which is why your reading 24% on bank two. Don't bother looking at anything else unless you're sure you've fixed your miss.

What could the miss be? Since your Ltrim is pegged, you can assume you're getting fuel in there so that leaves your ignition system or a vacuum leak specific to that cyl.

Mark

eallanboggs

iTrader: (1)

One nice thing about the LS1 is that it lends itself well to the SUBSTITUTION method of troubleshooting. Start swapping parts. Plugs, wires, coils, O2 sensors and monitor everything with AutoTap to see when the problem moves. It's unlikely your intake is loose unless you've been working on it. If you have or done any other work lately you need to go back over everything you did before you got the misfire on #6. Fix #6 and the other stuff will probably fall in line behind it.