idle problem / running rich on one side

[tjuranga]

Ok here we go I have a 94 tt that has a hunting idle between 1100rpm and near stall. The car hunts for a while then holds 1000rpm and does that over and over. Car fails CA smog, CO2 14.2, o2 .5, HC 199, co 1.26, NO 1511. Since then I have cleaned every conection, ohmed out the injectors they're all in spec, changed out all the vacuum lines, ohmed out all the coil packs one was suspect so I changed that all new plugs cleaned air filter and maf. On the ecu I get code 34 so ive ordered out for a new knock sensor. On the running test left o2 sensor blings on and off and on the right stays mostly on. Thinking of making a video of the problem to help let me know if you would like it.

Thanks

[stella90z]

I AM HAVING THIS SAME PROBLEM!!! It will drive well for the first maybe 5 to 10 minutes then the engine light will come on, go away then come on again for a minute then gone again and so on.and when that happens my car starts hesitating very bad and become powerless and I hear more back firing, until I shut it off for a while, then restart all over again. I can also hear a slight intake backfire sounds coming from the passenger side also. I tested the o2 and it was very inconsistent. Said I was running very rich. Left side responded good. Any help would be appreciated.i pulled the code 34 and code for right side o2 censor but was coming off and on while driving

[tjuranga]

Knock sensor and sub harness replaced with z1 upgrade. Still in safety boost still hunting idle and running rich. Please help

[tjuranga]

Ecu reset no codes now still have same problem and still only 5psi boost check the vid. https://www.youtube.com/watch?v=8IflwTq ... ata_player

[tjuranga]

Problem fixed. The low boost pressure was from the previous owner removing the factory "boost jets" when he upgraded the vacuum hosing. The erratic idle and running super rich on one side was a bad fuel dampener leaking a ton of fuel in to the vacuum signal line. Thanks for the help. Hope this helps some one else

[tjuranga]

sorry it took so long to get back got side tracked with moving up to Washington. So idle is finally fixed the first problem was the fule dampener was bad and dumping fuel in to the vacuum signal line. that took away the changing idle so it just idled high and ran constantly rich. for it only pushing five psi boost i found out when the previous owner redid the vacuum lines he removed the factory boost jets. i fixed that for now with an eBay boost controller. so then i had full boost but a constant rich condition and idle no lower than 1100 rpm, turns out i had bad injectors replaced them all and cleaned out the whole iaa assembly. z runs perfect now. thanks