8 codes-Lambda-cycles

J

JPCannonNC

Active member
May 8, 2015
37
0
North Carolina
www.cityofsaludanc.com
Back story,
I just rebuilt the top of the engine from the head gaskets all the way up. A lot of new parts including new O2 sensors, coil packs, spark plugs, cables, gaskets and more. Cranked the vehicle and it runs beautiful everyday for two weeks. Now for the last week it is throwing codes, codes and more codes. Fortunately the codes are the same codes over and over again after clearing them.
Code one is - Lambda sensor upstream catalyst bank 1.
Code 2-8 are similar to each other
- catalyst damaging misfire cycle 3
- catalyst damaging misfire cycle 5
- multiple cylinder misfire
- and similar

The first code makes since that the O2 sensor may need to be replaced even though it is a new one however I wonder if the remaining codes are throwing the first code or vice versa. I have tried following some of the cycle codes I have read in the forum, but my goodness it is hard to get every step completely perfectly especially now that it is throwing the series of codes faster than I can make it through the cycles I have found on the forum.
 
Rockbeard

Rockbeard

Well-known member
Jul 18, 2015
80
0
memphis, tn
is it actually physically misfiring? also, i hoped you didn't use dielectric grease on the o2 connectors. i'd check for a vacuum leak somewhere. if all else fails, a compression test may tell another story (hopefully not). it seems to be contained on the left bank so you should able to center your attention there. exhaust leakage can muck it up too.
 
J

JohnB

Well-known member
Oct 18, 2007
2,295
12
Oregon
Check and make sure the O2's are really plugged in tight. Also if you can watch live data of your O2's that should really help with diagnostics. Personally I'd stop clearing the codes and see what else pops up.

If its running good just normal driving will achieve readiness pretty quickly within a few runs around town, etc..those drive cycle threads aren't worth paying attention to.
 
D

discostew

Well-known member
Sep 14, 2010
7,733
1,024
Northern Illinois
Not sure what you mean when you say and similar. All 8 misfire codes? You say it ran good when you started it up for several days? What is the truck? Disco1 Disco2 ?

The drive cycle your trying to complete has worked every time if you can't get thru it. The drive cycle is intended to make conditions right for readiness tests to run.

Could you have switched the o2 sensor connectors from side to side? If you did that then the truck would run great til it goes into closed loop and then run like shit and throw all the codes you mentioned. Especially if you are working on a Disco1
 
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